Trilobites Spiky bursts of plasma called spicules swirl around the surface of the sun.
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As they unwind and release their tension, they fling hot plasma at incredible speeds, creating the spicules.
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The spicules surge thousands of miles high, passing through the chromosphere and into the sun's corona before collapsing.
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Its surface is covered in "microscopic hook-like glass spicules" that give the sea creature "a Velcro like surface," according to a press release by Fisheries and Oceans Canada.
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Using data gathered by high-powered land and space telescopes, they created a computer simulation that reconstructed the conditions between the sun's surface and its atmosphere, where spicules form.
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Juan Martínez-Sykora, an astrophysicist with Lockheed Martin as well as the Bay Area Environmental Research Institute and lead author of the study, said the team's next steps were to see if the spicules played a part in fueling the sun's corona and solar winds.
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Intrigued by this, he assembled a team to take a closer look and found that, while fossils of the hard parts of animals (shells, sponge spicules and so on) were common in all sedimentary layers, soft-tissue fossils were confined to six layers deposited at intervals of 100,000 years, or multiples thereof.
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Spicules are tables and large "C" bodies (S. horrens spicules). S. horrens many be found on reefs, below rocks on flats.
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Like most sponges, Capsospoingia had a spicular skeleton; long spicules parallel to the growth direction formed columns which were connected by shorter lateral spicules.
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Fossils of tunicates are rare because their bodies decay soon after death, but in some tunicate families, microscopic spicules are present, which may be preserved as microfossils. These spicules have occasionally been found in Jurassic and later rocks, but, as few palaeontologists are familiar with them, they may have been mistaken for sponge spicules.
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A. argyrosperma have siliceous spicules and collagen fibers to give it its form. Spicules are needle like structures which form the mineral skeleton. Megascleres are large spicules that form the main skeleton. Within A. argyrosperma the megascleres are slender, slightly curved acanthoxeas that range in length from 250- 329 µm and in width from 10-15 µm.
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Some apical actines, particularly those of young spicules, have only vestigial spines. Tripods are not abundant, as they are located only on the surface of external tubes. They are approximately the same length as the other spicules, but their actines are much more conical and stout. The centre of these spicules is frequently raised, and their tips are sharp.
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The basidia, spicules, and quaternate spores agree with those of Agaricini.
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Cells lining the gut of Pyura pachydermatina have been found to contain an insulin-like material in two forms that are immunologically active. The tissues of this tunicate are strengthened by the presence of two types of spicules. In the blood vessels in the tunic there are dogbone-shaped spicules and in the vessels in the body wall there are antler-shaped spicules. These spicules have a core of amorphous calcium carbonate enveloped in an insoluble layer of organic material with a thick exterior covering of calcite.
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Although the oscula is bigger than the ostia, both are extremely small and difficult to see. Spicules cover the thin dermal membrane, although the texture of the sponge itself is soft. The spicules are made of silica and provide structural support as well as protection. Freshwater sponge spicules come in many sizes and forms, including microscleres, emmula microscleres, and parenchyma macroscleres.
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These cells move within the walls of a sponge and form spicules.
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Spicules are equiangular and equiradiate triactines, tetractines, and tripods. Triactines are the most abundant spicules. The size of the triactines and tetractines is uniform. The actines of the triactines are conical or cylindrical, while the tetractines are always conical.
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It has been suggested that they represent the spicules of an ecdysozoan worm.
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The first Ediacaran and lowest Cambrian (Nemakit-Daldynian) skeletal fossils represent tubes and problematic sponge spicules. The oldest sponge spicules are monaxon siliceous, aged around , known from the Doushantou Formation in China and from deposits of the same age in Mongolia, although the interpretation of these fossils as spicules has been challenged. In the late Ediacaran-lowest Cambrian, numerous tube dwellings of enigmatic organisms appeared. It was organic-walled tubes (e.g.
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Anthaspidellidae is an extinct family of sponges whose dendroclone spicules form ladder-like trabs.
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The mantle spicules are composed of calcite (CaCO3) and brucite (Mg(OH)2) and fluorite (Ca2F), with calcite making up the largest percentage and fluorite the least. These deter predators by causing physical harm when the predator comes into contact with the spicules.
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Lyssacinosida is an order of glass sponges belonging to the subclass Hexasterophora. These sponges can be recognized by the parenchymal spicules usually being unconnected, unlike in other sponges in the subclass where the spicules form a more or less tightly connected skeleton.
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The spicules are curved cylinders, with pointed (oxea) or rounded (strongyloxea) tips at both ends.
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These characteristic spicules distinguish this sponge from any other sponge species found in the locality.
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Siliceous microfossils include diatoms, radiolarians, silicoflagellates, ebridians, phytoliths, some scolecodonts ("worm" jaws), and sponge spicules.
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Its spicules are slender and needle-like; the right spicule is longer than the left spicule or in some cases both spicules are equal in length. Its gubernaculum is narrow and long, with its proximal half being dorsally bent. The distal part of the gubernaculum possesses a transverse lamella-like structure on its dorsal side. The spicules and gubernaculum are well sclerotized, which are orange-coloured, the anterior part of which is colourless.
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Six-pointed spicule from a siliceous glass sponge Spicules are structural elements found in most sponges. They provide structural support and deter predators. Large spicules that are visible to the naked eye are referred to as megascleres, while smaller, microscopic ones are termed microscleres.
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The spicules are adhesive, and the sea cucumber is very difficult to detach from a wetsuit.
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Certain species have strange canoe-shaped spicules and these are all found in the Caribbean Sea.
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Osteons are components or principal structures of compact bone. During the formation of bone spicules, cytoplasmic processes from osteoblasts interconnect. This becomes the canaliculi of osteons. Since bone spicules tend to form around blood vessels, the perivascular space is greatly reduced as the bone continues to grow.
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Inside the bodies of individuals of Aiteng ater, there were found to be white elongated endoparasites; these are as yet unstudied. However the "parasites" described for Aiteng ater might represent spicules instead, because the presence of spicules is confirmed for the undescribed species Aitengidae sp. from Japan.
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There are about 3,00,000 active spicules at any one time on the Sun's chromosphere. An individual spicule typically reaches 3,000–10,000 km altitude above the photosphere.§1, Two Dynamical Models for Solar Spicules, Paul Lorrain and Serge Koutchmy, Solar Physics 165, #1 (April 1996), pp. 115–137, , .
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Its antennae are about the length of the head, and containing pointed spicules towards the inner side.
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The composition, size, and shape of spicules is one of the largest determining factors in sponge taxonomy.
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Males are characterized by spicules on their genitalia, which has a normal average of 45 spicules.Meiswinkel, R. Afrotropical Culicoides: Biosystematics of the Imicola Group. Subgenus Avaritia (Diptera: Ceratopogonidae), Ch. 3-5, 2013. However, variation is significant, as their quantity has been recorded to range from 8 to 145 spicules.
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Females have one ovary and the vulva located posterior. Males possess small spicules and small bursae or alae.
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The most accepted identity is that they are hexactinellid sponges, based on observed spicules, ostia, and internal structure.
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The meshing of many spicules serves as the sponge’s skeleton. It provides structural support and defense against predators.
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The molluscs are calcareous, as are calcareous sponges (Porifera), that have spicules which are made of calcium carbonate.
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Fibers made of sand, spicules, and spongin are also present, and aid in distinguishing the species from relatives.
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Spicules near the solar limb. They appear as dark "hairs" above the solar surface. In solar physics, a spicule is a dynamic jet of plasma, about 300 km diameterQuantifying Spicules, Tiago M. D. Pereira, Bart De Pontieu, and Mats Carlsson, The Astrophysical Journal 759, #1 (October 2012), pp. 18-34, , .
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The sea urchin embryo has been used extensively in developmental biology studies. The larvae form a sophisticated endoskeleton that is made of two spicules. Each of the spicules is a single crystal of mineral calcite. The latter is a result of the transformation of amorphous CaCO3 to a more stable form.
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Raphidonema faringdonense, a fossil sponge from the Cretaceous of England Although molecular clocks and biomarkers suggest sponges existed well before the Cambrian explosion of life, silica spicules like those of demosponges are absent from the fossil record until the Cambrian. One unsubstantiated report exists of spicules in rocks dated around . Well-preserved fossil sponges from about in the Ediacaran period have been found in the Doushantuo Formation. These fossils, which include spicules, pinacocytes, porocytes, archeocytes, sclerocytes and the internal cavity, have been classified as demosponges.
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This is likely because the sponges possess very little organic tissue; the siliceous skeleton accounts for 90% of the sponge body weight. Hexasterophoran sponges have spicules called hexactines that have six rays set at right angles. Orders within hexasterophora are classified by how tightly the spicules interlock with Lyssanctinosan spicules less tightly interlocked than those of Hexactinosan sponges. The primary frame-building sponges are all members of the order Hexactinosa, and include the species Chonelasma/Heterochone calyx (chalice sponge), Aphrocallistes vastus (cloud sponge), and Farrea occa.
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Hallaxa chani preys exclusively on Halisarca sp., a slick-textured dendroceratid sponge lacking both spicules and spongin fibers (Goddard, 1981, 1984, 1998). Like its congeners,Hallaxa chani is remarkably cryptic on its prey, both in color and texture. Both are tan to yellow-tan in color, and Hallaxa chani also lacks spicules.
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Amphidiscosida is an order of hexactinellid sponges characterized by amphidisc spicules, that is, spicules having a stellate disk at each end. They are in the class Hexactinellida and are the only order classified in the monotypic subclass Amphidiscophora. Species of the order Amphidiscosida have existed since the Ordovician period, and still flourish today.
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Some invertebrates use calcium compounds for building their exoskeleton (shells and carapaces) or endoskeleton (echinoderm plates and poriferan calcareous spicules).
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As the spicules continue to grow, they fuse with adjacent spicules and this results in the formation of trabeculae. When osteoblasts become trapped in the matrix they secrete, they differentiate into osteocytes. Osteoblasts continue to line up on the surface which increases the size. As growth continues, trabeculae become interconnected and trabecular bone is formed.
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Spicules are formed by sclerocytes, which are derived from archaeocytes. The sclerocyte begins with an organic filament, and adds silica to it. Spicules are generally elongated at a rate of 1-10 μm per hour. Once the spicule reaches a certain length it protrudes from the sclerocyte cell body, but remains within the cell’s membrane.
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The fingers have broad discs and some webbing between the last two fingers. The toes are about one-half webbed and have discs that are slightly smaller than those on the fingers. Males in reproductive state have the dorsum covered by spicules. The dorsum is dark green; the spicules appear off-white in living specimens.
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The surface of the sponge is smooth and ranges in colour from white, cream or orange to light grey. The silicaceous stiffening elements in the sponge's skeleton are called spicules, and the type and shape of these plays an important part in the identification of sponges. Homaxinella balfourensis has an axially condensed, choanosomal skeleton of spicules with an extra-axial skeleton of bundles of larger spicules known as megascleres. These come in various sizes but all are of the type known as styles, with one end pointed and the other end rounded.
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These spicules are classified as acanthostyles and consist of curved rods, with one end pointed and with whorls of spines on the shaft. The spicules are embedded in the sponge's tissues where they form a mesh-like, interlocking skeleton. The colour of this sponge is yellowish-brown, fawn or dark brown, sometimes with pale edges and it is said to resemble a piece of tanned cow-hide. It is similar in appearance to Agelas dispar but can be distinguished from that species by the size and shape of the spicules in its skeleton.
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Research on the Euplectella aspergillum (Venus' Flower Basket) demonstrated that the spicules of certain deep-sea sponges have similar traits to Optical fibre. In addition to being able to trap and transport light, these spicules have a number of advantages over commercial fibre optic wire. They are stronger, resist stress easier, and form their own support elements. Also, the low-temperature formation of the spicules, as compared to the high temperature stretching process of commercial fibre optics, allows for the addition of impurities which improve the refractive index.
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The spicules containing the basal portion of the upper tentacular part of the polyp of some soft corals (also called calice).
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Ray-like filaments radiate outwards from the edge of the bag. Some structures in the organism have been interpreted as spicules.
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The siliceous sponges form a major group of the phylum Porifera, consisting of classes Demospongiae and Hexactinellida. They are characterized by spicules made out of silicon dioxide, unlike calcareous sponges. Individual siliachoates (silica skeleton scaffolding) can be arranged tightly within the sponginocyte or crosshatched and fused together. Siliceous spicules come in two sizes called megascleres and microscleres.
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Hill, M., Lopez, N., & Young, K. (2005). Anti-predator defenses in western North Atlantic sponges with evidence of enhanced defense through interactions between spicules and chemicals. Marine Ecology Progress Series, 291, 93–102. doi:10.3354/meps291093 One of the most common structural strategies that sponges have that prevents them from being consumed by predators is by having spicules.
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Members of Scleraxonia have a skeletal axis made of calcified spicules, organic fibres or both, which may be separate, linked or fused together.
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It is common to find more coil in the posterior region. The males also have paired spicules but lack a gubernaculum and bursa.
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Eiffelia generally have star-shaped six-rayed spicules, with rays diverging at 60°, occasionally with a seventh ray perpendicular to the other six.
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Phasmids slightly posterior to mid-tail. Male is extremely rare, not essential for reproduction. Similar to female except for sexual dimorphism. Spicules slender.
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The first step in the process is the formation of bone spicules which eventually fuse with each other and become trabeculae. The periosteum is formed and bone growth continues at the surface of trabeculae. Much like spicules, the increasing growth of trabeculae result in interconnection and this network is called woven bone. Eventually, woven bone is replaced by lamellar bone.
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H. C. Schröder et al., Biosilica formation in spicules of the sponge Suberites domuncula: Synchronous expression of a gene cluster. Genomics 85, 666 (2005).H. C. Schröder et al., Apposition of silica lamellae during growth of spicules in the demosponge Suberites domuncula: Biological/biochemical studies and chemical/biomimetical confirmation. Journal of Structural Biology 159, 325 (2007).F. Natalio et al.
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The sclerocytes are responsible for the secretion of spicules. In species of sponges that use spongin instead of calcaerous and silicaceous spicules, the sclerocytes are replaced by spongocytes, which secrete spongin skeletal fibres. The myocytes and porocytes are responsible for contraction of the sponge. These contractions are analogous to muscle contractions in other organisms, since sponges do not have muscles.
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Takakkawia is a genus of sponge in the order Protomonaxonida and the family Takakkawiidae. It is known from the Middle Cambrian Burgess Shale that reached around 4 cm in height. Its structure comprises four columns of multi-rayed, organic spicules (perhaps originally calcareous or siliceous) that align to form flanges. The spicules form blade-like structures, ornamented with concentric rings.
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The three groups are differentiated by the extent of fusion of adjacent spicules. The Lyssacinosa, Hexactinosa, and Lychniscosa appear sequentially in the fossil record. The least fused group, the Lyssacinosa, appears in the Ordovician, while the intermediate group, the Hexactinosa is known from the Devonian. Finally, the Lychniscosa, with the most tightly interlocking spicules is first found in rocks of Triassic age.
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Spongolite texture, click to enlarge (2MB) Spongolite is a stone made almost entirely from fossilised sponges. It is light and porous. The silica spicules fossilised with the sponges makes the material hazardous to handle by being highly abrasive. Because the spicules are embedded in soft fossils, the abrasion damage is not as immediately apparent as it would be from sandpaper or rough bricks.
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The tips of these spicules project through the cuticle and help give traction during locomotion which is performed by peristalsis, synaptids having no tube feet.
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Ulospongiella is a genus of sponge known only from the Burgess Shale deposit. It contains only one species, Ulospongiella ancyla. The generic name is derived from the Greek words oulus ("wooly" or "curly") and spongia ("sponge"), referring to the curled or curved spicules forming the skeleton. The specific name, ancyla, is from the Greek ankylos ("bent" or "hooked"), also referring to the curved spicules.
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Calcarea (with encrusting crinoid) from the Middle Jurassic Matmor Formation of Makhtesh Gadol, Israel. The calcareous sponges of class Calcarea are members of the animal phylum Porifera, the cellular sponges. They are characterized by spicules made out of calcium carbonate in the form of calcite or aragonite. While the spicules in most species have three points, in some species they have either two or four points.
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A short, fat, globular species, it generally does not exceed 8 in (20 cm), though 5 in (13 cm) is seldom exceeded. Its skin is thick and covered in highly modified scales called dermal spicules. These spicules are prickly in appearance and resemble the warts of a toad. The frogfish has small eyes, a very large mouth that is directed upwards, and pectoral fins situated on stalks.
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Depending on context, that process also may be called atmospheric icing. The ice it produces differs in some ways from crystalline frost, which consists of spicules of ice that typically project from the solid surface on which they grow. The main difference between the ice coatings and frost spicules arises from the fact that the crystalline spicules grow directly from desublimation of water vapour from air, and desublimation is not a factor in icing of freezing surfaces. For desublimation to proceed the surface must be below the frost point of the air, meaning that it is sufficiently cold for ice to form without passing through the liquid phase.
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Some species prefer certain sizes and types of rock particles; other species are preferential towards certain biological materials. Certain species of foraminifera are known to have preferentially agglutinated coccoliths to form their tests; others preferentially utilise echinoderm plates, diatoms, or even other foraminiferans' tests. The foraminifera Spiculosiphon preferentially agglutinates silica sponge spicules using an organic cement; it shows strong selectivity also towards shape, utilising elongated spicules on its "stalk" and shortened ones on its "bulb". It is thought to use the spicules as both a means of elevating itself off the seabed as well as to lengthen the reach of its pseudopodia to capture prey.
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These fossil spined echinoid sea urchins can reach a diameter of about , with spicules of about 69x60mm. They are hemispherical, flattened beneath, with small apical disc.
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A male that reinitiates the mating program, only to intromit his spicules into the same partner, is at a competitive disadvantage to disseminate his genetic material.
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Grantia is a genus of calcareous sponges belonging to the family Grantiidae. Species of the genus Grantia contain spicules and spongin fibers. The genus contains bioluminescent species.
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Males have spicules. Females have a single ovary which is reflexed and prodelphic. The spermatheca is offset. This species is described as very active and fast-moving.
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Fossils of glass sponges have been found from around in rocks in Australia, China and Mongolia. Early Cambrian sponges from Mexico belonging to the genus Kiwetinokia show evidence of fusion of several smaller spicules to form a single large spicule. Calcium carbonate spicules of calcareous sponges have been found in Early Cambrian rocks from about in Australia. Other probable demosponges have been found in the Early Cambrian Chengjiang fauna, from .
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Peruvispira), scyphozoa (e.g. Conularia), crinoid stalks, foraminifera (Hyperammina, Ammodiscus, Glomospira, Ammobacculites and Spiroplectammina),Bangert, 2000, p.60 sponges and sponge spicules, radiolaria, coprolites and permineralised wood.Bangert, 2000, p.
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They have thick smooth leathery skin which is strengthened with calcareous spicules; some of these are plates pierced by more than four holes, and others are cup- shaped.
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Individuals are unicellular and spherical, usually around 30–80 μm in diameter, and covered with long radial axopods, narrow cellular projections that capture food and allow mobile forms to move about. A few genera have no cell covering, but most have a gelatinous coat holding scales and spines, produced in special deposition vesicles. These may be organic or siliceous and come in various shapes and sizes. For instance, in Raphidiophrys the coat extends along the bases of the axopods, covering them with curved spicules that give them a pine-treeish look, and in Raphidiocystis there are both short cup-shaped spicules and long tubular spicules that are only a little shorter than the axopods.
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It has no calcareous spicules, but it has integumental concrements. It has no keel on the visceral hump. It has aggregations of precerebral ‘accessory ganglia’. It has no eyes.
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Borojevia tetrapodifera is a species of calcareous sponge from New Zealand. The species is named after the presence of tetrapods, the only Clathrinid sponge known to possess such spicules.
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P. lateolabracis can be distinguished from the former by the lateral caudal mounds separated dorsally, narrower lamella-like structures on its gubernaculum, shorter spicules, and by the testis extending anteriorly. Other gonad-infecting species differ from this one by possessing a smooth gubernaculum, and their spicules being of different lengths. Seven gonad- infecting species of Philometra can be distinguished from P. priacanthi by their host types, as well as by geographical distribution.
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At () long, Spiculosiphon oceana is the largest foraminifera found in the Mediterranean. The species creates a test (shell) made out of sponge spicules, "gluing" them together with a protein it secretes, much like sponges do. The spicules it uses are carefully selected and laid parallel to the main stalk of the creature. Because of its large size and its appearance, S. oceana was originally mistaken as a multi-cellular animal from the sponge family.
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Leucosolenida is an order of sponges in the class Calcarea. Species in the order Leucosolenida are calcareous with a skeleton composed exclusively of free spicules without calcified non-spicular reinforcements.
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Adults of this species are reported to grow to 0.4–0.6 mm long. They possess two alae. The body is defended by a thin cuticle. The males possess asymmetrical spicules.
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Archaeocytes are along with other specialized sponge cells including collencytes and structural elements called spicules. They move about within the mesohyl with amoeba-like movements performing a number of important functions.
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220) by Félix Dujardin as a subgenus of the genus Ascaris Linnaeus, 1758. Dujardin did not make explicit the etymology, but stated that the subgenus included the species in which the males have unequal spicules ("mâles ayant des spicules inégaux"); thus, the name Anisakis is based on anis- (Greek prefix for different) and akis (Greek for spine or spicule). Two species were included in the new subgenus, Ascaris (Anisakis) distans Rudolphi, 1809 and Ascaris (Anisakis) simplex Rudolphi, 1809.
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Spicules are tiny glass flakes which are formed during the manufacture of glass vials. A glass tube is extruded at a constant rate and a jet of water applied to the hot glass is used to cut the blank tube to length. The bottom and lip of the vial are formed by swagging or upset forming while the glass is still hot. Spicules are formed in a cloud when the glass explodes from the contact of the cold jet.
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This is in contrast to the spicules of a sponge such as Clathrina which has a calcite core, a thick layer of amorphous calcium carbonate and a thin outer covering of calcite.
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Each lobe has one opening (oscule) about in diameter, either located flush on the surface or elevated in small chimneys. The spicules are composed solely of strongyles, cylindrical in shape with rounded ends.
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Caryophyllidia are an anatomical feature of the external dorsal surface of dorid sea slugs. Caryophyllidia are sensory tubercles, surrounded by tiny needle-like structures called spicules, that are present on the outer mantle.
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The thin peristome is continuous. This species is remarkable for the coronal of equidistal abbreviated spicules, which denote the uppermost and most strongly developed of the spiral lirae in the two lowest whorls.
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Peltodoris has two main defense mechanisms that have been confirmed: mantle spicules and disruptive coloration. Unlike most dorid species, Peltodoris do not utilize chemical defense through the absorption of cytotoxic chemicals from their prey.
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Dorsal skin bears only relatively small warts. The male lacks the hypertrophied forearm and the keratinised spicules on the skin of the throat and on the basis of the arms seen in Petropedetes newtonii.
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They form from the redeposition of amorphous silica arising from the dissolution of siliceous spicules of sponges, or debris from radiolaria and the postdepositional replacement of either the enclosing limestone or chalk by this silica.
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Ecionemia is a genus of sea sponges belonging to the family Ancorinidae. This genus is characterized by a high density of siliceous spicules. Members of this genus are known to be eaten by hawksbill turtles.
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Placospongia is a genus of sea sponges belonging to the family Placospongiidae. This genus is characterized by a high density of siliceous spicules. Members of this genus are known to be eaten by hawksbill turtles.
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Females are about 38 to 63 mm long. This genus of Brugia is most commonly recognized by the spicules in males, which are needle like mating structures that open the vulva of the female worm. In the Brugia genus, there are two spicules, they are the shortest in length, the left one being 200–215 μm and the right one 75–90 μm long. Despite the fact that males have certain characteristics that help key this species out, the females lack those key characteristics.
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In addition, these spicules have built-in lenses in the ends which gather and focus light in dark conditions. It has been theorized that this ability may function as a light source for symbiotic algae (as with Rosella racovitzae) or as an attractor for shrimp which live inside the Venus' Flower Basket. However, a conclusive decision has not been reached; it may be that the light capabilities are simply a coincidental trait from a purely structural element. Spicules funnel light deep inside sea sponges.
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Demosponges constitute about 90% of all known sponge species, including all freshwater ones, and they have the widest range of habitats. Calcareous sponges, which have calcium carbonate spicules and, in some species, calcium carbonate exoskeletons, are restricted to relatively shallow marine waters where production of calcium carbonate is easiest. The fragile glass sponges, with "scaffolding" of silica spicules, are restricted to polar regions and the ocean depths where predators are rare. Fossils of all of these types have been found in rocks dated from .
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Thyone fusus has an oval body up to long. The anterior (front) end has a mouth surrounded by a circle of ten branching tentacles while the posterior (back) end bears the anus and is bluntly rounded. There are a few tube feet, and these may be arranged in longitudinal rows. The skin is smooth and fine with few calcareous spicules; these spicules are usually table-shaped, with four holes and a pair of fused rods making a spire, and may also be present in the tube feet.
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Epimenia babai, a member of the Solenogastres Aplacophorans are worm-like animals, with little resemblance to most other molluscs. They have no shell, although small calcified spicules are embedded in the skin; these spicules are occasionally coated with an organic pellicle that is presumably secreted by microvilli. Caudofoveates lack a foot while solenogasters have a narrow foot which lacks intrinsic musculature. The mantle cavity is reduced into a simple cloaca, into which the anus and excretory organs empty, and is located at the posterior of the animal.
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The Besa River Formation is composed primarily of dark shale. Sandstone, bedded chert or limestone beds can occur at the top of the formation. The shale is slightly calcareous or siliceous and contains sponge spicules and radiolarians.
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Mature males have hooks with blunt tips on their posterior ends. Its body is wider on the upper half of its body and has an annulated abdomen. They also contain hooked copulatory spicules that aid in mating.
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This large species of chiton grows to be about 7 cm (3 inches) in length. It has oval shaped body with dimpled plate margins, a brown girdle with eight overlapping plates, long calcareous spicules and dark bands.
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In shallow water the colonies are small, the colour is more intense and there are more spicules present making the external surface bright white. At greater depths the colonies are larger, there are fewer spicules and the colour is more greyish or brownish. The tunic exudes large quantities of mucus which makes this species sticky to the touch. It is very similar to Atriolum robustum in appearance, especially young colonies, but can be distinguished by the mucus secretion and the network of canals connecting the thorax internally to the atrial siphon.
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In contrast to all other molluscan classes, the Aplacophora have no shell, and are instead covered by aragonitic sclerites (calcareous spicules), which can be solid or hollow. These spicules can be arranged perpendicular to one another within the cuticle to form a skeleton, or can stick up to form a palisade, or can lie flat against the cuticle. 80% of solenogaster species have a radula, while in others it is secondarily lost. The radula may bear one or more teeth per row; where there is more than one tooth, there is no central radular tooth.
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The St. Johns culture is defined in terms of pottery styles. Plain chalky ware was the dominant St. Johns ceramic type. ("Chalky" ware was made from clay taken from fresh water sources, which contained spicules from fresh water sponges. The spicules in the clay helped strengthen the pottery, and created a "chalky" surface, soft enough to be scratched with a fingernail.)Pelotes Island Nature Preserve - Woodland Period - St. Johns Cultures - 500 BC to 1500 AD - Retrieved July 17, 2007 "Exotic" ceramic ware is common, especially in ceremonial contexts.
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Gene 395, 62 (2007). Silica deposition begins intracellularly and is carried out by the enzyme silicatein.W. E. G. Müller et al., Identification of a silicatein(-related) protease in the giant spicules of the deep-sea hexactinellid Monorhaphis chuni.
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The animal uses its proboscis to probe in muddy gravel or in sand, searching for food. It feeds on macro algae particles, benthic diatoms Pleurosignia sp., on detritus and also remains of animal matter, such as sponge spicules.
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Rhinophore-sheath with smooth margin. Branchial plumes 6, small, simply pinnate, completely retractile within a cavity with smooth margin. Foot produced behind in a fairly long tail, the anterior end abruptly rounded and simply labiate. Integument with spicules.
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The class demosponges are the most abundant and diverse of the sponge classes. Some of the sponges in this class have skeletons made from silicon-containing spicules, spongin fibers, or both. Demosponges include both marine and freshwater sponges.
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Large, irregular and loosely anastomosed tubes form the cormus. The spicules are very bright and can easily be seen. The mesohyl has many porocytes with brown granules. The skeleton has no special organization, comprising equiangular and equiradiate triactines.
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Suberites are key examples of the importance of the extracellular matrix in animals. In sponges, it is mediated by proteoglycans. Spicule formation is also important for Suberites. Spicules are structural support of sponges, similar to skeletons in higher animals.
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The male has winglike folds surrounding its cloaca. Its sex organs include a pair of flanged spicules and a protruding gubernaculum to guide them during mating. The female has a rounded or hemispherical tail with a spike-shaped tip.
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When the male finds the female, he will coil around the female over the genital pore. The male's spicules are used to hold the female during copulation. The females are ovoviviparous. The sperm of a nematode lacks a flagellum.
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Food capture by kinetocysts in the heliozoon Raphidiophrys contractilis. European Journal of Protistology, 37(4), 453-458. doi:10.1078/0932-4739-00847. The nucleus can be found in the periphery of the cell . Organic spicules have been found on Raphidiophrys heterophryoidea .
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In very young animals, the notum is translucent and has a herringbone pattern of embedded white spicules beginning between the rhinophores and ending at the gills.Pittman, C. & Fiene, P., 2018. Thorunna daniellae Sea Slugs of Hawaii, accessed 2018-12-23.
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As the larva grows, it not only adds spicules to its casing but pieces of the sponge itself. When the ceraclea reaches adulthood and leaves the sponge, it carries and disburses fragments, thus facilitating the formation of new sponge colonies.
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Preserved specimens are dorsally brown and ventrally white. Males shave hypertrophied forearms, dorsal spine on the distal edge of the metacarpal of the first finger, keratinised spicules on arms and tympanic borders, large thenar tubercle, and well-developed humeral crest.
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Kulindroplax seems adapted to moving through a substrate, with the spicules acting as "sediment ratchets". In contrast with some modern aplacophorans like the caudofoveates, which live within the sea bottom sediments, Kulindroplax probably crawled on the bottom, requiring a dorsal armour.
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The species is usually brownish black, with valves incised with radiating wavy lines; these may be heavily eroded in older specimens. The broad and velvety girdle is brown to black and bears tiny embedded spicules. Adult size is 20–50 mm.
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It is characterized by the absence of oesophageal teeth, the presence of conspicuously inflated papillae of the last two subventral pairs, a gubernaculum, spicules 69–75 µm long, eggs measuring 57–66 × 39–45 µm, and a small body (between long).
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In zoology a skeleton is any fairly rigid structure of an animal, irrespective of whether it has joints and irrespective of whether it is biomineralized. The mesohyl functions as an endoskeleton in most sponges, and is the only skeleton in soft sponges that encrust hard surfaces such as rocks. More commonly the mesohyl is stiffened by mineral spicules, by spongin fibers or both. Spicules, which are present in most but not all species,Halisarca dujardini - Marine Species Identification Portal may be made of silica or calcium carbonate, and vary in shape from simple rods to three-dimensional "stars" with up to six rays.
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Posterior end of a male nematode, Gongylonema pulchrum, showing right spicule and gubernaculumphilometrid nematode - E and F represent the gubernaculum In nematodes, the gubernaculum is a hardened or sclerotized structure in the wall that guides the protrusion of the spicule during copulation. For example, in Caenorhabditis elegans, spicules serve to open and dilate the vagina of the hermaphrodite and the gubernaculum is a grooved plate in which the spicules move; the gubernaculum is controlled by two erector and two protractor muscles. The shape and size of the gubernaculum are often important characters for the systematics of nematodes.
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The grey wall sponge may grow to 10 cm thick and 40–50 cm in length. It is a massive grey sponge with fine spicules protruding from its surface. It has a stony texture, with small oscula visible on the upper surface.
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Verongiida (also known as Verongida) is an order of sea sponges within the phylum Porifera. The "skeleton" in these sponges is made up of spongin, rather than of spicules. They live in marine environments. The name was proposed by Patricia Bergquist in 1978.
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Two thread-like projections spicules originate from the cloaca. The female is considerable larger, about 4–5 cm long and 0.23 mm to 0.33 mm in diameter. The tail is bluntly rounded. There is a single anus, but sucker and papillae are absent.
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The testis is single, and its duct opens into the intestine and is provided with two chitinous spicules. The ovary is also single, opening independently and anterior to the anus. The nervous system is as yet unknown. Genera include Desmoscolex, Greeffiella, and Tricoma.
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The interstices show extremely fine and regular spicules. The suture runs straight and is not very distinct, giving the whorls a subulate aspect. The aperture is narrowly oval with a bright porcellaneous aspect. The siphonal canal is short, truncate and slightly askew.
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Ancorina is a genus of sea sponges belonging to the family Ancorinidae. It is the type genus of its family. This genus is characterized by a high density of siliceous spicules. Members of this genus are known to be eaten by hawksbill turtles.
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The inside is light brown. Surface is smooth. Oscules are grouped in more or less shallow depressions (= preoscules) while pores are spread over the whole body. There is a distinct cortex about 0.5 mm thick, it is made of ball-shaped spicules called sterrasters.
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Their depositional environment was a shallow marginal sea with rather high accumulation rates of 30 meters/million years. Besides radiolarians sponge spicules are very prominent in these sediments.Iljima, A. et al. (1978). Shallow-sea, organic origin of the Triassic bedded chert in central Japan.
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This article incorporates CC-BY-2.0 text from the reference.Todt C. & Wanninger A. (2010). "Of tests, trochs, shells, and spicules: Development of the basal mollusk Wirenia argentea (Solenogastres) and its bearing on the evolution of trochozoan larval key features". Frontiers in Zoology 7: 6. .
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The key to morphologically identifying O. ostertagi males is a prominent proconus and the remainder of the genital cone is not prominent. The spicules are of equal length and shape, tapering towards the distal end.Taylor, M. A., Coop, R. L., and Wall, R. L. 2015.
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Fossils recovered from the Phosphoria Formation include brachiopods, sponge spicules, crinoid stems, conodont elements, and fish scales and bones. The Early Permian age of the formation is based primarily on conodont biostratigraphy.Wardlaw, B.R. and J.W. Collinson, 1986. Paleontology and deposition of the Phosphoria Formation.
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The cuticle contains calcareous spicules which are star-shaped. This sea cucumber may be confused with Aslia lefevrei. Both live in crevices with their dark-coloured tentacles projecting; P. saxicola is white, but may darken somewhat when exposed to light, while Aslia lefevrei is brown.
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Geodia is a genus of sea sponge belonging to the family Geodiidae. It is the type genus of its taxonomic family. This genus is characterized by a high density of siliceous spicules. Members of this genus are known to be eaten by hawksbill turtles.
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Above the central tube, it is possible to see some lacunes. The skeleton is formed of two types of triactines, of different sizes, and tetractines of the same size as the shorter triactines. The spicules are equiradiate and equiangular. Actines are conical with sharp tips.
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They also have simple spicules, which allow for direct sperm transfer. In the female, the vulva is about one- third the body length from the anterior end. The ovaries are very large and extensive. The uteri contain up to 27 million eggs at a time.
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When environmental conditions become less hospitable to the sponges, for example as temperatures drop, many freshwater species and a few marine ones produce gemmules, "survival pods" of unspecialized cells that remain dormant until conditions improve; they then either form completely new sponges or recolonize the skeletons of their parents. In most sponges, an internal gelatinous matrix called mesohyl functions as an endoskeleton, and it is the only skeleton in soft sponges that encrust such hard surfaces as rocks. More commonly, the mesohyl is stiffened by mineral spicules, by spongin fibers, or both. Demosponges use spongin; many species have silica spicules, whereas some species have calcium carbonate exoskeletons.
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For decades, researchers believed spicules could send heat into the corona. However, following observational research in the 1980s, it was found that spicule plasma did not reach coronal temperatures, and so the theory was discounted. As per studies performed in 2010 at the National Center for Atmospheric Research in Colorado, in collaboration with the Lockheed Martin's Solar and Astrophysics Laboratory (LMSAL) and the Institute of Theoretical Astrophysics of the University of Oslo, a new class of spicules (TYPE II) discovered in 2007, which travel faster (up to 100 km/s) and have shorter lifespans, can account for the problem. These jets insert heated plasma into the Sun's outer atmosphere.
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4(6), pp.414-416[Peer After tooth extraction, the residual crest irregularities, undercuts or bone spicules should be removed, because they may result in an obstruction in placing a prosthetic restorative appliance. Recontouring can be made at the time of extraction or at a later time.
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Hexactinellid sponges are sponges with a skeleton made of four- and/or six- pointed siliceous spicules, often referred to as glass sponges. They are usually classified along with other sponges in the phylum Porifera, but some researchers consider them sufficiently distinct to deserve their own phylum, Symplasma.
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The girdle is studded with spines of spiculed setae. ;Setae The setae are very distinct if viewed under a scanning electron microscope. They have flat and broad setae, which bare 4 rows of large, curved white calcareous spicules. These are up to 600 micrometers in length.
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Halichondriidae is a family of sea sponges belonging to the order Suberitida.A systematic revision of the central West Atlantic: Halichondrida (Demospongiae, Porifera). Part III: Description of valid species These sponges have a skeleton consisting of dense bundles of spicules occurring in a more or less random pattern.
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Shallow water Octocorallia of the West Indian Region. Studies of the fauna of Curacao and other Caribbean islands. 55. Sclerite examination is necessary for species identification, which reveals the characteristic 4-rayed 'butterfly' spicules of the cortex and the lack of purple sclerites in the axial sheath.
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S. ficus does not have many predators. This may be because it has an unpleasant odour or because the spicules make it unpalatable. It is eaten however by some marine gastropods and some nudibranchs. It forms part of the diet of the Atlantic bluefin tuna (Thunnus thynnus).
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Crambeidae is a family of marine demosponges.Register of Marine Species Identification of members of this family of sponges is based on microscopic examination of the spicules in their skeleton. The megascleres consist of peripheral thinner subtylostyles and thicker choanosomal styles while the microscleres are exclusively anchorate chelae.
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The Heteractinids are a grade of sponges that are paraphyletic with respect to Hexactinellida. Their distinctive trait is their six-pronged (snowflake-like) spicules, whose symmetry historically suggested a relationship with the triradial Calcarean sponges. Nevertheless, they actually represent a polyphyletic grade, from which the hexactinellids arose.
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Foam of soap bubbles Foams obey Plateau's laws, which require films to be smooth and continuous, and to have a constant average curvature. Foam and bubble patterns occur widely in nature, for example in radiolarians, sponge spicules, and the skeletons of silicoflagellates and sea urchins.Philip Ball. Shapes, 2009.
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W. E. G. Müller et al., Luciferase a light source for the silica-based optical waveguides (spicules) in the demosponge Suberites domuncula. Cellular and Molecular Life Sciences 66, 537 (2009). In effect, the siliaceous structures act as fiber optic cables to convey light signals generated from the protein luciferase.
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Milanich 1993. Milanich 1995. Between 500 and 1000, the undecorated, sand-tempered pottery that had been common in the area was replaced by "Belle Glade Plain" pottery. This was made with clay containing spicules from freshwater sponges (Spongilla), and it first appeared inland in sites around Lake Okeechobee.
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Some of the sponges they eat, such as Aaptos aaptos, Chondrilla nucula, Tethya actinia, Spheciospongia vesparium, and Suberites domuncula, are highly (often lethally) toxic to other organisms. In addition, hawksbills choose sponge species with significant numbers of siliceous spicules, such as Ancorina, Geodia (G. gibberosa), Ecionemia, and Placospongia.
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Male Leptodactylus petersii measure and females in snout–vent length. The dorsum ranges from greenish or greyish brown to reddish brown and has irregular dark brown to black markings. There is also a dark, triangular inter-orbital mark. The dorsum bears many spicules and short, laterally oriented glandular ridges.
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Calcaronea is a subclass of sea sponges in the class Calcarea. They are Calcarea with the triactines and the basal system of tetractines sagittal (i.e. the rays of the spicule make unequal angles with each other), exceptionally regular. In ontogeny the first spicules to be secreted are diactines.
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The gut is continuous throughout the branches, but has been found to contain very few of the sponge's spicules. One possible solution to this puzzle is that the worm may be surviving on dissolved organic carbon absorbed through its integument, as some other invertebrates, including polychaete worms, do.
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This species is conspicuous for the nine paired tufts or rosettes of long glassy spines that decorate its girdle. Between the tufts, the girdle bears many smaller spicules. The valves are of a dull brown color and marked with oblique pale stripes. They are largely concealed by the girdle.
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Water-collecting tubes converge into one apical osculum. Colour white in ethanol and light beige when dried. Triactines from the clathroid body range from almost regular to parasagittal with straight actines. Close to the peduncle there are parasagittal spicules with the longest unpaired actine pointing towards the peduncle.
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The girdle may be ornamented with scales or spicules which, like the shell plates, are mineralized with aragonite - although a different mineralization process operates in the spicules to that in the teeth or shells (implying an independent evolutionary innovation). This process seems quite simple in comparison to other shell tissue; in some taxa, the crystal structure of the deposited minerals closely resembles the disordered nature of crystals that form inorganically, although more order is visible in other taxa. The protein component of the scales and sclerites is minuscule in comparison with other biomineralized structures, whereas the total proportion of matrix is 'higher' than in mollusc shells. This implies that polysaccharides make up the bulk of the matrix.
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Elpidia is a genus of deep-sea sea cucumbers. Members are characterised by their rod-shaped spicules which each have two pairs of obliquely-placed horizontal arms and two vertical apophyses. There is a high degree of endemism in this genus with different species occupying different deep sea basins or regions.
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Internally there are large cavities, many primary canals across and narrow secondary canals. There is a fibrous, tightly-meshed skeleton made of spongin with ascending and tangential fibres. The spicules consist of bundles of acanthostyles (one end blunt, one end pointed and covered with 7 to 12 whorls of spines).
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Spicules are found in a range of symmetry types. Monaxons form simple cylinders with pointed ends. The ends of diactinal monaxons are similar, whereas monactinal monaxons have different ends: one pointed, one rounded. Diactinal monaxons are classified by the nature of their ends: oxea have pointed ends, and strongyles are rounded.
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Stolonifera is a suborder of soft corals in the order Alcyonacea. Members of this taxon are characterised by having separate polyps budding off an encrusting horizontal, branching stolon. The skeletons include spicules or consists of a horny external cuticle. These soft corals are found in shallow tropical and temperate seas.
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Philometra lagocephali is a species of parasitic nematode of fishes, first found off New Caledonia in the South Pacific, in the abdominal cavity of Lagocephalus sceleratus. This species is characterized mainly by: length of spicules and length and structure of its gubernaculum; body size; location in host and types of hosts.
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S. Dak. Agric. Exp. Sin. 31. Females have two ovaries which overlap the spermatheca. The vulva is found near the center of the body and the rectum near the tip of the tail. Males are smaller than the female, have an arcuate spicules, gubernaculum with titillate and a broad striated bursa.
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Most sponges are too rough for general use due to their structural spicules composed of calcium carbonate or silica. But two genera, Hippospongia and Spongia, have soft, entirely fibrous skeletons. These two genera are most commonly used by humans. It is unknown when exactly the sponge became an article of use.
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Suberites ficus is a species of sponge in the family Suberitidae. It is sometimes known as the sea orange sponge. Sponges are primitive animals with little apparent internal organisation. They are composed of a jellylike mesohyl sandwiched between two layers of cells and have a fragile skeleton composed of stiff spicules.
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Phthipodochiton body is worm-like, with eight polyplacophoran-like valves but no true foot. Head and tail valves are slightly smaller than the intermediate ones. The only ornaments on the valves appear to be growth lines. The body is also covered by a sheet of spicules ; no radula has been preserved.
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This small purse sponge grows singly and is globular in shape, sometimes with a short stalk. It is up to eight centimetres long and may be grey, yellowish or white. At the tip is an osculum fringed with long, upright spicules. The surface of the sponge is hairy and the consistency soft.
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Calcinea in which the cormus is formed by anastomosed tubes covered by a thin membranous layer, at least in young specimens. Cormus is massive/globular with or without a stalk. The skeleton contains regular (equiangular and equiradiant) triactines and tetractines, but parasagittal triactines may be present. Triactines are the most numerous spicules.
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Whereas males grow to only about in length, females can grow from . Both sexes also possess a tiny buccal capsule and cylindrical esophagus without a posterior bulb. In the free-living stage, the esophagi of both sexes are rhabditiform. Males can be distinguished from females by two structures: the spicules and gubernaculum.
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A treatise on zoology. Volume 2. London, A. and C. Black 1900 The functions of the collencytes are not yet fully understood; they are branched amoeboid cells and appear to produce collagen and play roles in forming sponge spicules. It even has been proposed that they have primitive nerve-like physiologic roles.
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Like other Thelenota, T. rubralineata contains calcareous spicules in the form of granules and branched rods. Located throughout the body wall, these structures serve as both structural support and defense from predators. Two Polian vesicles provide the basis for locomotion. 5 longitudinal muscles are broad, V-shaped, and attached to the body wall.
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Nematomorphs can be confused with nematodes, particularly mermithid worms. Unlike nematomorphs, mermithids do not have a terminal cloaca. Male mermithids have one or two spicules just before the end apart from having a thinner, smoother cuticle, without areoles and a paler brown colour.Malcolm S. Bryant, Robert D. Adlard & Lester R.G. Cannon 2006.
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Thysanozoon nigropapillosum is quite common along the external reef in the shallow sub-tidal zone. It can swim by undulating and rhythmically contracting the body margins. It feeds on tunicates, using its mouth and large pharynx to engulf Didemnum spp., and later regurgitates food pellets containing the calcareous spicules present in their tunics.
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A trab is structural element within a sponge formed by the fusion of dendroclones. In the Anthaspidellidae, when spicules (usually dendroclones) connect at their tips to form a ladder-like structure, trabs may be formed. Oxeas are sometimes employed in the central rod. Trabs have a feather-like structure, or may form rods.
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In some genera this is permeated with a calcareous substance in the form of fused spicules. Members of this suborder are characterized by having an unspiculated axis and often a soft, chambered central core.Suborder Holaxonia Guide to the Shallow Water (0-200 m) Octocorals of the South Atlantic Bight. Retrieved 2011-12-05.
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Didemnum is a genus of colonial tunicates in the family Didemnidae. It is the most speciose genus in the didemnid family. Species in this genus often have small calcareous spicules embedded in the tunic and form irregular or lobed colonies. Some Didemnum species, including Didemnum vexillum and Didemnum perlucidem are considered invasive species.
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Coronacollina acula is a multicellular organism from the Ediacaran period resembling the Cambrian 'sponge' Choia. The organism comprised a raised, tri- radially-symmetrical central mound with a central depression and resistant spicules (up to four in articulated fossils), which were resistant — either chitinous or biomineralized — and grew to be 37 cm long.
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Males: Outline of lip region is more flattened at the sides than in females but arrangement of lobes is similar. The testis is outstretched. Spicules are arcuate with ventral flanges and the distal ends pointed with small apical notches. The gubernaculum is well developed and there is a bursa enveloping the tail.
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Type specimens of Spiculosiphon oceana SEM images of sponge spicules covering the stalks of S. oceana Spiculosiphon oceana is a giant species of foraminifera (a phylum of unicellular eukaryotes). Its appearance and lifestyle mimics that of a sponge. It was discovered in 2013 in underwater caves 30 miles off the coast of Spain.
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The girdle spines often bear length-parallel striations. The wide form of girdle ornament suggests it serves a secondary role; chitons can survive perfectly well without them. Camouflage or defence are two likely functions. Spicules are secreted by cells that do not express "engrailed", but these cells are surrounded by engrailed- expressing cells.
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C. oncophora females are about 6–8 mm long, males about 5.5–9 mm. They are light red in color and have a coiled shape. Male worms have a large bursa as shown in Figure 2a. The spicules are 240-300 µm long and have a rounded end and a longitudinal line pattern.
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They eat by holding the fish in one claw and tearing the flesh with the other. Eagles have structures on their toes called spicules that allow them to grasp fish. Osprey also have this adaptation. Bald eagles have powerful talons and have been recorded flying with a mule deer (Odocoileus hemionus) fawn.
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Clathrina coriacea is a species of calcareous sponge belonging to the family Clathrinidae. This species occurs as flat white or yellow encrustations up to 3 cm in diameter with a central osculum. Close inspection reveals a tightly- knit latticework of tubes. The spicules are all of a similar shape, three- rayed triactines.
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Scientists disagree about this: Giribet and colleagues concluded, in 2006, the repetition of gills and of the foot's retractor muscles were later developments, while in 2007, Sigwart concluded the ancestral mollusc was metameric, and it had a foot used for creeping and a "shell" that was mineralized. For a summary, see In one particular branch of the family tree, the shell of conchiferans is thought to have evolved from the spicules (small spines) of aplacophorans; but this is difficult to reconcile with the embryological origins of spicules. The molluscan shell appears to have originated from a mucus coating, which eventually stiffened into a cuticle. This would have been impermeable and thus forced the development of more sophisticated respiratory apparatus in the form of gills.
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Scientists disagree about this: Giribet and colleagues concluded, in 2006, the repetition of gills and of the foot's retractor muscles were later developments, while in 2007, Sigwart concluded the ancestral mollusc was metameric, and it had a foot used for creeping and a "shell" that was mineralized. For a summary, see In one particular branch of the family tree, the shell of conchiferans is thought to have evolved from the spicules (small spines) of aplacophorans; but this is difficult to reconcile with the embryological origins of spicules. The molluscan shell appears to have originated from a mucus coating, which eventually stiffened into a cuticle. This would have been impermeable and thus forced the development of more sophisticated respiratory apparatus in the form of gills.
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Sycon raphanus is a species of marine invertebrate, a calcareous sponge belonging to the family Sycettidae. The name derives from the Greek, "raphanus", meaning radish, and presumably refers to the sponge's shape. Sponges are composed of a jellylike mesohyl sandwiched between two layers of cells. They have a fragile skeleton composed of stiff spicules.
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Males can be distinguished by their bell-like copulatory bursa, located in the tail, and their paired rodlike spicules. Eggs are ovular in shape and range from 50 to 100 micrometres in size; they closely resemble those of hookworms, which renders diagnosis via stool analysis useless in areas co-infected with both Oesophagostomum and hookworm.
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Halisarcidae is a family of sea sponges within the order Chondrillida. Members of the family are characterised by having long tubular, branched choanocyte chambers; they have no spicules which makes it difficult to determine the group's affinities with other sponge families. Halisarcidae is a monogeneric family, the only genus being Halisarca.Vacelet, J.; Donadey, C. (1987).
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The Flammenmergel gets its name from its "flamed" or "burnt" appearance. According to JORDAN(1968), this appearance is caused by the tracks of burrowing organisms, which consist primarily of siliceous sponge spicules which have been washed into the burrows.Jordan, H. (1968): Gliederung und Genese des Flammenmergels (Alb) in Hils- und Sackmulde. Z. dt. Geol. Ges.
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Paxton et al. (2001) Like other whalefish, it has a generally whale- shaped body, small pectoral and pelvic fins, and dorsal and anal fins set far back. Body and fins are covered with tiny spicules, resulting in a velvety feel that inspires the name. Colour is an overall vivid geranium red or dark orange.
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Guayasamin et al. (2008) Their color is green above, with a rich scattering of small, white spots – hence the species' scientific name, which means "the powdered one". The back has a rough shagreen-like texture, particularly in males, where it is covered in tiny spicules. The belly is transparent and has a grained texture.
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The dorsum is dark green while the venter is aquamarine. The tips of the digits are yellowish green, and margin of the upper lip is greenish white. The iris is dull bronze with fine, black reticulations. Dorsal skin is smooth but bears many minute, white spicules, which have given the species its specific name spiculata.
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An individual of Notodoris minor crawling Notodoris minor can grow to 14 cm in length. The skin is toughened with tiny spicules. The upper surfaces have a few irregular pustules, while the small rhinophores are smooth and simple. The branched gills are located midway along the body and are partially hidden by three large lobes.
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Larval stages are poorly known, but those described are slender, narrowed anteriorly, with groups of ventral spicules on creeping welts. The larva is amphipneustic (having only the anterior and posterior pairs of spiracles). The mandibles are simple, hooked, and without additional teeth. The parastomal bars are long, thin structures, fused to the tentoropharyngeal sclerite.
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Three of these bands of tube feet are found on bottom whereas the top rows are often reduced. Adults of C. frondosa have a reduced numbers of spicules (skeletal structures) shaped like rounded plates with many holes.Levin, V. S., and Gudimova, E. N. 2000. Taxonomic interrelations of holothurians Cucumaria frondosa and C. japonica (Dendrochirotida, Cucumariidae).
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Species of Clathrina have a tubular organization as all species of the family Clathrinidae, with the cormus composed of anastomosed tubes. The skeleton contains spicules in the form of triactines and/or tetractines, sometimes with diactines, tripods and tetrapods as well. The choanoderm is usually flat, never forming folds when the sponge is extended.
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All the stems have 10-18 spiny vertical ridges that contain silica spicules. The leaves are scales fused into sheaths that cover the stems and branches. These spiny leaves are larger and looser on the fertile stems. The fertile stems are shorter than the others; on these develop the cones that bear the spore casings.
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The exact shape of these spicules is important for identification purposes and in this family there are a range of different sclerites including foliate capstans and spheroids, plain spindles, plain capstans and small and large clubs. Members of this family do not have the unicellular symbiotic algae Zooxanthellae that grows in the tissues of many other corals.
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These sponges are massive or encrusting in form and have a very simple structure with very little variation in spicule form (all spicules tend to be very small). Reproduction is viviparous and the larva is an oval form known as an amphiblastula. This form is usual in calcareous sponges but is less common in other sponges.
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Sycon ciliatum is a species of calcareous sponge belonging to the family Sycettidae. Sponges are marine invertebrates with a jellylike mesohyl sandwiched between two layers of cells. They are filter feeders maintaining a flow of water through their structure which passes out through large openings called oscula. They have a fragile skeleton composed of stiff spicules.
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They are distinguished by a siliceous skeleton of two and four rayed spicules and contain the protein spongin. Hexactinellid are also called glass sponges, and are distinguished by a six-rayed glass skeleton. These sponges are also capable of carrying out action potentials. Calcareous sponges are characterized by a calcium carbonate skeleton and comprise less than 5% of sponges.
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It is probably derived from sponge spicules or other siliceous organisms as water is expelled upwards during compaction. Flint is often deposited around larger fossils such as Echinoidea which may be silicified (i.e. replaced molecule by molecule by flint). Chalk, as seen in Cretaceous deposits of Western Europe, is unusual among sedimentary limestones in the thickness of the beds.
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The cloud sponge takes the form of a large cup with an irregularly folded wall about thick. This is pierced by many pores about wide and covered by a thin dermal membrane. The skeletal elements form a lattice-like structure made up of fused spicules of silica. These mesh together and project into the adjoining canals.
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The axopods are arranged into distinct rows, six of which lie in a dorsal groove and are rigid, and the rest of which are mobile. These are used primarily for buoyancy, rather than feeding. They also have fourteen groups of prominent spines, and many smaller spicules, although there is no central capsule as in true radiolarians.
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Adult T. canis are found only within dogs and foxes and the males are 4–6 cm in length, with a curved posterior end. The males each have spicules and one “tubular testis.” Females can be as long as 15 cm, with the vulva stretching one third of their bodylength. The females do not curve at the posterior end.
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289-297 The geology of the area is particularly interesting. The coastline in the area is formed from rocks and shingle with exposed cliffs behind. The Middle White Oolite of the Osmington Oolite more visible to the west has descended to beach level here. At the middle of the cliff, there is nodular rubble consisting of calcitized sponge spicules.
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Growth forms are varied and include branching, club-shaped, massive and encrusting. Identification of members of this family is based on microscopic examination of the spicules in their skeleton. The choanosomal skeleton is composed of tornotes while the ectosomal skeleton consists of a tangential crust of spined styles or oxeas. The microscleres are mostly arcuate isochelae.
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The type-species of the genus, Prospinitectus mollis was first described as Spinitectus mollis Mamaev, 1968, and redescribed from two males by Petter in 1979. The genus was differentiated on the base of several morphological characters, including the pseudolabiae, the buccal capsule, the cuticle with spines arranged as rings, the number of papillae in the male and the spicules.
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The surface of hemipenes is one of the most interesting and unique features, and is often covered in sharp spines and spicules that are organized in formations called rosettes. However, species with relatively smooth hemipene surfaces also exist. For example, the hemipenis of the Siamese spitting cobra (Naja siamensis) is smooth with blunt ends, while that of the many-spotted cat-eyed snake (Boiga multomaculata) is entirely covered in hooked spines and spicules. Yet despite this assortment of hemipenis designs, no association has been found between the design of hemipenes and the disposition or danger of the animal. Rather, it is believed that hemipenes found in the squamate world exhibit such diverse designs to facilitate mating compatibility amongst individuals of the same species, a theory that is referred to as the “lock-and-key mechanism”.
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The Carterinids, including the genera Carterina and Zaninettia, have a unique crystalline structure of the test which long complicated their classification. The test in this genus consists of spicules of low-magnesium calcite, bound together with an organic matrix and containing "blebs" of organic matter; this led some researchers to conclude that the test must be agglutinated. However, life studies have failed to find agglutination, and in fact the genus has been discovered on artificial substrate where sediment particles do not accumulate. A 2014 genetic study found carterinids to be an independent lineage within the Globothalamea, and supported the idea of the spicules being secreted as spicule shape differed consistently between specimens of Carterina and Zaninettia collected from the same locality (ovoid in Carterina, rounded-rectangular in Zaninettia).
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The ecology of gastropterids has been little studied, but most Sagaminopteron species have been observed to feed on sponges that do not contain spicules. At least some Siphopteron species are found on macroalgae and seagrasses. Gastroperids are simultaneous hermaphrodites. Siphopteron species have a complex mating behaviour, with each of two slugs attempting to use spines for hypodermic insemination of the other one.
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Retrieved 2012-02-12. The minute calcareous spicules that are embedded in the skin are characteristic for the species, being square or round and table-shaped with spires formed of four pillars.An illustrated key to the sea cucumbers of the South Atlantic Bight Retrieved 2012-02-12. The colour is dark greenish-brown or charcoal grey with pale grey tentacles on blackish stems.
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U. dioica close-up of the defensive hairs Leaf detail. A hand with nettle dermatitis Urtica dioica produces its inflammatory effect on skin (stinging, burning sensation often called "contact urticaria") both by impaling the skin via spicules - causing mechanical irritation - and by biochemical irritants, such as histamine, serotonin, and acetylcholine, among other chemicals.Nettle (Stinging). Wildflowerfinder.org.uk. Retrieved on 3 July 2012.
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However, they do have many of the same receptors and signals found in higher animals.X. Wang, X. Fan, H. Schröder, W. Müller, Flashing light in sponges through their siliceous fiber network: A new strategy of 'neuronal transmission' in animals. Chinese Science Bulletin 57, 3300 (2012). Researchers in China and Germany have found that sponge spicules contribute to their neural communication.
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They have pores, called ostia, that water travels through to a chamber called the spongocoel, and exits through a chamber called the osculum. Through this water filtration system, they obtain nutrients that are needed for their survival. Specifically, they intracellularly digest bacteria, micro- algae or colloids. Sponge skeletons consist of either spongin or calcareous and siliceous spicules with some collagen molecules interspersed.
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Anheteromeyenia argyrosperma have a thin, encrusting form with a hispid surface due to emerging spicules. Their color is grey unless green from being in symbiosis with zoochlorellae (algae). Their bodies are permeated with pores, chambers, and canals for the flow of water through them. The smaller, more prevalent incurrent pores are the ostia and the larger excurrent pores are the oscula.
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O. ostertagi adults are slender reddish-brown worms. Adult males are long, adult females long, and the eggs long. Identification of adult medium stomach worms is based on the structure of the bursa, genital cone, and spicules in males and on the dimensions of the oesophageal valve and the configuration of the synlophe in males and females.Lichtenfels JR, H. E. 1993.
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Modern sponges are widely agreed to be descendants of the earliest cell colonies that evolved into modern animals. The earliest fossil evidence for sponges are tiny sponge spicules, which first appeared very close to the end of the Proterozoic era. They probably evolved as protection, as well as support, during the great arms race at the start of the Cambrian explosion.
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Kieselkalk is also known as the Helvetic Siliceous Limestone. It has sedimented during the Lower Cretaceous epoch. It can contain up to 40% of very fine (1-10 μm), evenly distributed authigenic quartz crystals. Early diagenetic dissolution of opal sponge spicules led to silica enrichment of interstitial waters, which reprecipitated silica in the overlying horizons, forming tiny quartz crystals in pore spaces.
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E. godeffroyi is a long, slender sea cucumber growing to a length of about . A ring of fifteen feathery tentacles encircle the mouth. The body colour is creamy white with blotches of grey and a pair of longitudinal brown or greenish stripes. The spicules (microscopic calcareous structures that project through the skin) are a mixture of anchors and perforated plates with large holes.
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Hexactinellids, or "glassy" sponges are characterized by a rigid framework of spicules made of silica. Unlike other poriferans, hexactinellids do not possess the ability to contract. Another unique feature of glassy sponges is that their tissues are made up almost entirely of syncytia. In a syncytium there are many nuclei in a continuous cytoplasm; nuclei are not packaged in discrete cells.
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The growth of sponge reefs is thus analogous to that of coral reefs. The tendrils of new sponges wrap around spicules of older, deceased sponges. The tendrils will later form the basal plate of the adult sponge that firmly anchors the animal to the reef. Deep ocean currents carry fine sediments that are captured by the scaffolding of sponge reefs.
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Echinaster feed mostly on biofilms, encrusting invertebrates, such as sponges, and microalgae. One study performed showed that sea stars of the Echinaster have no problem eating the spicules of sponges, along with the sponge skeleton. Studies also showed that the Echinaster prefer sponge species that lack chemical defenses.[18] They are the least likely to eat sponges with a rubbery texture.
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The feeding polyps secrete a sticky mucus to trap tiny organisms suspended in the water. The colony’s rigidity and purple color come from calcium carbonate spicules throughout the polyp’s tissues. The sea pansy is strikingly bioluminescent when disturbed because of the interplay between a luciferase (Renilla-luciferin 2-monooxygenase) and green fluorescent protein (GFP). Both molecules have recently become extremely important in biology.
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Radiospongilla sceptroides is a species of freshwater sponge in the family Spongillidae. It was described as Spongilla sceptroides by Scottish-born Australian zoologist William A. Haswell in 1883, who discovered it growing on submerged wood in a pond in the vicinity of Brisbane. He described it as "Sponge green, encrusting, smooth, moderately elastic, not crumbling." He noted the spicules were fusiform and pointed.
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Spiculosiphon oceana lives on the sea floor. It lies in wait and extends its pseudopods outside its shell to capture prey, primarily plankton, that get trapped on the spicules of its shell. Thus, it captures prey much in the same way as carnivorous sponges. In addition to the visual and lifestyle similarities of S. oceana and sponges, the creatures live in similar habitats.
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Kulindroplax is about wide and long. It is the first known mollusk showing an unambiguous combination of valves, or exterior shells, and a worm-like body. It bears seven similar, unarticulated valves, with a shorter head valve and a taller caudal one, lacking ornaments and also several densely packed, long spicules. It has no discernible foot, and the radula is not preserved.
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Lamina dura, along with the periodontal ligament, plays an important role in bone remodeling and thus in orthodontic tooth movement. Under the lamina dura is the less bright cancellous bone. Trabeculae are the tiny spicules of bone crisscrossing the cancellous bone that make it look spongy. These trabeculae separate the cancellous bone into tiny compartments which contain the blood producing marrow.
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Actinopyga echinites grows to a length of about . It is widest in the middle, tapering slightly at both ends; the dorsal surface is arched while the ventral surface is flattened. The leathery skin is rough, being covered in papillae. The skin is strengthened by the presence of spicules, microscopic spike-like structures, which in this species are shaped like large rods.
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The head has conical tentacles, white and solid. The black digestive gland is seen by transparency in the center of the sole of the foot and of the flanks. The whole surface of the mantle is upholstered with tubercles of caryophyllidia of equal form and shape, arranged tightly and with a bundle of spicules that barely protrudes from the tubercle.
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The skeleton has no special organisation, and it comprises triactines, tetractines and tripods. Triactines and tetractines are equiangular and equiradiate; their actines are slightly conical, with blunt tips. Triactines are the most abundant spicules; the apical actine is shorter and thinner than the facial ones. It is also straight, conical, and unlike that of B. brasiliensis and B. cerebrum, smooth.
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Members of the family Melithaeidae are arborescent colonial corals forming fans, bushes or trees. The axis or main skeletal "trunk" is jointed, there being nodes, flexible horny joints, separated by internodes composed of hard, calcareous material. The branches divide dichotomously at the nodes and these are often swollen. The minute calcareous spicules in the flexible membrane called the mesoglea that covers the skeleton are called sclerites.
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Bohadschia marmorata is cylindrical in shape and grows to about long. The body wall is tough and leathery and has a rough texture due to the calcareous spicules it contains. It is covered in translucent papillae up to across and a few short spines. The anterior end of the body is somewhat narrowed and has a mouth surrounded by a ring of retractile tentacles.
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Colochirus quadrangularis is a moderate sized sea cucumber growing to about in length. The roughly cylindrical body has four longitudinal ridges giving it a square cross section and a flat base. It has irregular, thorn-like, soft projections called papillae lying along these ridges. The leathery body wall is reinforced by calcareous spike-like structures which in this species include basket- shaped spicules and perforated ellipsoids.
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They contain a matrix composed of proteins and spicules. Archaeocytes are special types of cells, in that they can transform into all of the other cell types. They will do what is needed in the sponge body, such as ingest and digest food, transport nutrients to other cells in the sponge body. These cells are also capable of developing into gametes in some sponge species.
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Other carbonate grains composing limestones are ooids, peloids, intraclasts, and extraclasts. Limestone often contains variable amounts of silica in the form of chert (chalcedony, flint, jasper, etc.) or siliceous skeletal fragment (sponge spicules, diatoms, radiolarians), and travertine (a precipitate of calcite and aragonite). Secondary calcite may be deposited by supersaturated meteoric waters (groundwater that precipitates the material in caves). This produces speleothems, such as stalagmites and stalactites.
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A group of Bioclastic wackestone is present, and consists of a micro-matrix with plenty of thin shell remains scattered loosely. Furthermore are Echinoderm remains, Ostracodes, foraminifera, radiolaria and represented spiculae. Authentic Pyrite is found in patches to observe. There is an alternate deposition composed mostly by bioclastic wackestone with Echinoderm remains, and other with Mudstone, with abundant echinoderms, foraminifera, Gastropods, echinid spines and pebble spicules.
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Acanthotetilla celebensis is a species of sea sponge belonging to the family Tetillidae. It is only known from a single specimen collected at a depth of 14 m off Bunaken Island, north Sulawesi, Indonesia. This firm yellow sponge] is roughly hemispherical and around 12 cm across. Like other species of the genus Acanthotetilla, it is characterized by the presence of distinctive spiny spicules called "megacanthoxeas".
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Raphidiophrys heterophryoidea is the first organism to show a combination of scales and spicules in one species amongst heliozoans demonstrating a transitional state observed at least twice in centrohelid evolution . This is important because of suspicions that like other hacrobians, centrohelids may have haploid and diploid stages that are morphologically different (in centrohelids the ploidy of these morphologically different stages has never been shown).
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There is a fir-tree like concentration of spicules running through the body wall with the branches either having rounded or knobbly ends. The form of the sponge varies according to the location in which it is found. It often has a mitten-like structure or may be tall and cylindrical or bowl-like but in areas with strong currents can be dense and compact.
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The Chalk Group is a sequence of Upper Cretaceous limestones. The dominant lithology is relatively soft porous white chalk with only poorly-defined bedding. The chalk is classified as a biomicrite, with microscopic coccoliths and other fine-grained fossil debris in a matrix of micrite mud. Small amounts of silica were also deposited, mainly from sponge spicules, which moved during diagenesis and accumulated to form flints.
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Sandwiched between the outer lamina and the inner lining is the "median layer", a protein layer that separates the two. The median layer is quite variable; depending on the species it may be well-defined while in others it is not sharply delineated. Some genera may contain sediment particles within the median layer. SEM photomicrograph of a carterinid test wall, showing secreted calcite spicules in organic matrix.
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The colony is firmly attached to a hard surface from which it can be difficult to detach. D. vexillum has different forms in different locations. It can form a thin or thick encrusting mat, or form large or small lobes. The colour can be orange, pink, tan, creamy yellow or greyish-white and the tunic is sparsely strengthened by stellate spicules with nine to eleven rays.
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Spicules are produced by sclerocyte cells, and may be separate, connected by joints, or fused. Some sponges also secrete exoskeletons that lie completely outside their organic components. For example, sclerosponges ("hard sponges") have massive calcium carbonate exoskeletons over which the organic matter forms a thin layer with choanocyte chambers in pits in the mineral. These exoskeletons are secreted by the pinacocytes that form the animals' skins.
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They are enclosed in a sheath (egg shell) which are easily stained with Giemsa stain (but not for B. timori). The sheath protects them while moving in the blood stream. Species of Brugia are similar to W. bancrofti and Loa loa. But they can be differentiated from their smaller microfilariae, complex spicules, and fewer caudal papillae (typically 11, while it is 24 in W. bancrofti).
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Monorhaphis is also the only genus in the monotypic family Monorhaphididae. One study provides substantial evidence that an individual of this deep-sea sponge, that forms giant spicules up to 3 meters long, is about 11,000 years old.Jochum KP, Wang X, Vennemann TW, Sinha B, Müller WEG. Silieous deep-sea sponge Monorhaphis chuni: A potential paleoclimate archive in ancient animals. Chem Geol. 2010;300–301:143–151.
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Hymeniacidon kitchingi is a species of sponge in the class Demospongiae. It is found in shallow waters in the northeastern Atlantic Ocean. This species was first described in 1935 by the British zoologist Maurice Burton. He placed it in a new genus because of its unusual spicules, and named it Rhaphidostyla kitchingi, in honour of Dr J. A. Kitching, who had collected the original specimen.
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There is also typically an internal digestive chamber. The eukaryotic cells possessed by all animals are surrounded by a characteristic extracellular matrix composed of collagen and elastic glycoproteins. This may be calcified to form structures like shells, bones, and spicules, a framework upon which cells can move about and be reorganized during development and maturation, and which supports the complex anatomy required for mobility.
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Spongilla Lacustris are filter eaters that consume small floating organic particles. They are consumed by Sisyridae, a group of winged insects also known as sponge flies. Their larvae act as parasites on the sponge and feed exclusively on it during its larval period. Ceraclea are insects that not only feed on the sponges but will use the sponges' spicules to build hard, protective cases for themselves.
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The hairs lining the seed pods contain serotonin and the protein mucunain which cause severe itching when the pods are touched. The calyx below the flowers is also a source of itchy spicules and the stinging hairs on the outside of the seed pods are used in some brands of itching powder.G. V. Joglekar, M. B. Bhide J. H. Balwani. An experimental method for screening antipruritic agents.
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This soft coral was first described in 1766 by the Russian naturalist Peter Simon Pallas who named it Parerythropodium coralloides. It was later determined on the basis of its growth forms, the nature of its spicules (small skeletal elements) and the passages in its coenenchyme (the tissue uniting the polyps) that it should be included in the genus Alcyonium and it was renamed Alcyonium coralloides.
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Brenner also chose it as it is easy to grow in bulk populations, and convenient for genetic analysis. Alt. URL It is a multicellular eukaryotic organism, yet simple enough to be studied in great detail. The transparency of C. elegans facilitates the study of cellular differentiation and other developmental processes in the intact organism. The spicules in the male clearly distinguish males from females.
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Male A. cantonensis spicules (arrows), scale bar is 85 µm A. cantonensis is a helminth of the phylum Nematoda, order Strongylida, and superfamily Metastrongyloidea. Nematodes are roundworms characterized by a tough outer cuticle, unsegmented bodies, and a fully developed gastrointestinal tract. The order Strongylida includes hookworms and lungworms. Metastrongyloidea are characterized as 2-cm- long, slender, threadlike worms that reside in the lungs of the definitive host.
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Members of the genus Melithaea are arborescent colonial corals forming fan, bush or tree shapes. The axis or main skeletal "trunk" is jointed, there being nodes, flexible horny joints, separated by internodes composed of hard, calcareous material. The branches divide off at the nodes which are often swollen. The minute calcareous spicules in the flexible membrane called the mesoglea that covers the skeleton are called sclerites.
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The identity of these spicules is important for identification purposes and in this genus they are predominantly double discs and small disc-spindles, but also include plain spindles, capstans and small clubs. Members of this genus do not have the unicellular symbiotic algae Zooxanthellae in their tissues that many other corals do. Colonies vary in colour but tend to be shades of yellow, orange, red and brown.
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Onchidoris proxima is oval in shape and grows to a length of about . The head has a flattened piece of tissue above the mouth. The mantle is covered with club-shaped tubercles with pointed ends which are stiffened with calcareous spicules (spine-like structures). The body is a yellowish- orange colour, but is often quite a pale shade, especially in the northernmost part of the animal's range.
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Snails and sponge spicules have also been found in the stomachs of a few individuals, and in captivity they are known to consume any food offered to them. The large numbers of S. thermophilus found on sulfur crusts where there are no obvious prey items may feed directly on filaments of chemosynthetic bacteria. If so, this would represent a hitherto unknown behavior for vent fish species.
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Clathrina cribrata is a massive species with its body formed from a network of large, irregular tubes. Some of these extend above the main body of the sponge as blind tubes and others are open-ended, serving as osculi. This sponge contains only one type of calcareous spicule. These are three-rayed spicules, known as triactines, and are distributed throughout the tissues in an unorganized way.
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Embryologic mesenchymal cells (MSC) condense into layers of vascularized primitive connective tissue. Certain mesenchymal cells group together, usually near or around blood vessels, and differentiate into osteogenic cells which deposit bone matrix constitutively. These aggregates of bony matrix are called bone spicules. Separate mesenchymal cells differentiate into osteoblasts, which line up along the surface of the spicule and secrete more osteoid, which increases the size of the spicule.
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The distinguishing characteristics of this nematode are a well-developed metacorpus from J2 through adult, a short stylet 11-15 μm in adults, adults typically 1mm in length. Females have the vulva located two-thirds body length and have a vulval flap. Females have a long post uterine sac and a rounded tail. Males have seven papillae in the tail region, distinct spicules, and bursa shaped as a spade.
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The mesohyl is composed of the following main elements: collagen, fibronectin-like molecules, galectin, and a minor component, dermatopontin. These polypeptides form the extracellular matrix which provides the platform for specific cell adhesion as well as for signal transduction and cellular growth. The mesohyl includes a noncellular colloidal mesoglea with embedded collagen fibers, spicules and various cells, being as such a type of mesenchyme.Brusca, R.C. & Brusca, G.J. (2003). Invertebrates.
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In medusae the only supporting structure is the mesoglea. Hydra and most sea anemones close their mouths when they are not feeding, and the water in the digestive cavity then acts as a hydrostatic skeleton, rather like a water-filled balloon. Other polyps such as Tubularia use columns of water-filled cells for support. Sea pens stiffen the mesoglea with calcium carbonate spicules and tough fibrous proteins, rather like sponges.
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The skeleton is covered by a flexible membrane, the mesoglea, which contains minute calcareous spicules or sclerites. The identity of these is important for distinguishing between different closely related species. In Melithaea ochracea, they include capstans, double discs, disc-spindles and unilaterally spinose spindles, plain spindles, clubs and anthocodial sclerites. Three sides of the branches are densely covered in calyces, dome shaped perforated structures from which the polyps protrude.
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During copulation, one or more chitinized spicules move out of the cloaca and are inserted into the genital pore of the female. Amoeboid sperm crawl along the spicule into the female worm. Nematode sperm is thought to be the only eukaryotic cell without the globular protein G-actin. Eggs may be embryonated or unembryonated when passed by the female, meaning their fertilized eggs may not yet be developed.
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Its penis is armed with many spines. It lays its spawn in loose white coils. When these nudibranchs respond to a threat, they adopt a defensive posture: they flatten their body allowing numerous spicules to penetrate through the body wall, so that the nudibranch assumes the aspect of a hedgehog, covered in spines. The numerous glands on the body wall also probably contribute to the effectiveness of this defensive posture.
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Coenenchyme is the common tissue that surrounds and links the polyps in octocorals. It consists of mesoglea penetrated by tubes (solenia) and canals of the gastrodermis and contains sclerites, microscopic mineralised spicules of silica or of calcium carbonate. The stiff projecting portion of coenenchyme that surrounds each polyp is usually reinforced by modified sclerites and is called the calyx, a term borrowed from botany. "Coenosarc" is an alternative name.
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The species female is long and wide. The body have strong convex of the dorsum. Their lateral keels are flaring from the third segment and middle of the body and ending on the sides of metazonides. The surface is the same for all segments that don't have setae or spicules, but is coated everywhere else with organic matter, which is quite thin on tubercles of the apex part.
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The gills are situated in the center of the dorsal side, they are yellow and protected by three round lobes. The body is stiff and protected by small spicules. The rhinophores are smooth, simple, yellow and retractable. Notodoris gardineri can be mistaken for Notodoris minor, whose body colour is also yellow with black markings except that in the latter the black forms lines on the body and not spots.
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Jackstone calculi are rare bladder stones that have an appearance resembling toy jacks. They are almost always composed of calcium oxalate dihydrate and consist of a dense central core and radiating spicules. They are typically light brown with dark patches and are usually formed in the urinary bladder and rarely in the upper urinary tract. Their appearance on plain radiographs and computed tomography in human patients is usually easily recognizable.
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Females are different from males in that they possess only two large papillae around their slightly rounded posterior ends. From the side view, the dorsal outline is rounded, whereas the ventral side appears flat. Males have eight caudal papillae encompassing the anus on their bluntly rounded ends. Characteristic of males is the presence of blunt spicules that play the important reproductive role of holding open the vagina during sperm transfer.
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In common with other Alcyonacea, red corals have the shape of small leafless bushes and grow up to a meter in height. Their valuable skeleton is composed of intermeshed spicules of hard calcium carbonate, colored in shades of red by carotenoid pigments. In living specimens, the skeletal branches are overlaid with soft bright red integument, from which numerous retractable white polyps protrude. The polyps exhibit octameric radial symmetry.
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Maasella edwardsi forms small groups in which the polyps are linked by stolons. The anthocodia, the upper part of the polyp, can be fully retracted back into the anthostele, the stiff, lower part. Each anthocodia bears eight tentacles, each with ten to thirteen short pinnules on each side. The anthostele is broader than the anthocodia and is stiffened by calcareous spicules which are sometimes visible as white markings.
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A modification in the posterior end of the esophagus forms a muscular posterior bulb, which can generate a pumping action similar to that of a metacorpus in other plant parasitic nematodes. The number of males varies from abundant to sparse depending on the species. Males have paired spicules but the gubernaculum and bursa are absent. Males of different species can be characterized using the varying number and arrangement of papillae.
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The novaculite beds of the south-central United States were deposited in the Ouachita Geosyncline, a deep-water marine trough, during Silurian to early Mississippian time. Sedimentation consisted primarily of siliceous skeletal particles of marine organisms such as sponge spicules and radiolaria, and very fine-grained, wind-blown quartz particles; there was very little argillaceous sedimentation during novaculite deposition.McBride, E.F. and Thomson, A. 1970. The Caballos novaculite, Marathon region, Texas.
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Here, the benefit of utilizing ACC may not be for physical strength, but for its periodic need of the exoskeleton to be dissolved for molting. Sea urchins and their larvae utilize the transient form of ACC when forming spicules. The new material, a hydrated form of ACC, for the spicule is transported and deposited at the outer edges of the spicule. Then the deposited material, ACC·H2O, rapidly dehydrates to ACC.
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Morphology: Adult has two lateral lips, dorsal and ventral lips may also be present. Buccal capsule cylindrical, chitinous. Oesophagous is divided into two parts, a short anterior muscular and long posterior glandular portion, intestine simple without any diverticula. Male: spicules unequal, gubernaculum present and bears 4 pairs of preanal, 1 pair adanal and 2 pairs of postanal pedunculated papillae, 3 pairs of sessile papillae also present, tail spirally twisted.
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No trichoxeas were found, but these spicules are sometimes difficult to find. Klautau and Valentine therefore decided not to consider the presence of trichoxeas in their description. Klautau and Valentine elevated this variety to the status of a species because C. ceylonensis is very distinct from C. coriacea. Despite morphological similarities, such as the presence of water-collecting tubes and the size of the triactines, they can easily be distinguished.
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Rasheedia novaecaledoniensis is a parasitic nematode in the genus Rasheedia. The species is an intestinal parasite of the Indian goatfish Parupeneus indicus (Mullidae) off New Caledonia.The two species Rasheedia novaecaledoniensis and Rasheedia heptacanthi, which both occur in New Caledonian waters, are mainly differentiated by the number of anterior protrusible oesophageal lobes (two in R. heptacanthi and four in R. novaecaledoniensis), structure of the oesophagus and the lengths of their spicules.
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The tunic is strengthened by the presence of many spherical calcareous spicules which are particularly concentrated round the neck of the urn. The colony is white, brown or green, or some combination of these colours. This hue is due to the symbiotic blue- green algae of the genus Prochloron present in the tissues. The tunic contains mycosporins which filter out ultra-violet radiation and protect the symbiotic cyanobacteria from damage in strong sunlight.
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On the ecology of a dense bed of the brittle star Ophiothrix fragilis. Journal of the Marine Biological Association of the United Kingdom, 51, 267-282. However its glassy spicules may make it unpalatable, it lives in concealed places and is well camouflaged so that it blends in with its surroundings which combine to reduce predation. A study of skeletal bands suggests that it may live for as many as ten years.
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Halisarca caerulea is a thinly encrusting species forming patches about thick. The texture is fleshy, and the skin is strengthened by the presence of bundles of collagen fibres which give a reticulated pattern to the smooth, slightly slimy surface. This sponge has long tubular, choanocyte chambers, which are sometimes branched, and no spicules. The oscula are about in diameter, each being at the centre of a conspicuous star-shaped group of superficial canals.
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The last segment has 2 tubercles which are submedian. The gonopods look a lot like those of C. hispidulosus, with only two differences; the current species does not have spicules and has limited organic coating. It also has a hidden outer joint, with a lateral surface and large tubercle which is also rounded. They also have two small and transverse tubercles which are located on the sternum of their ninth row of legs.
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Missouri had a varied fauna during the ensuing Ordovician period. Ordovician life in the state included abundant branching bryozoans, tabulate corals, tetracorals, abundant crinoids, graptolites, abundant pelecypods, nautiloids (generally straight shelled, but sometimes coiled), Receptaculites, sponges (which left behind spicules), and trilobites (which were uncommon in the Early Ordovician). Graptolites were preserved in Jefferson and Pike counties, with the Jefferson County graptolites being the better preserved. Armored fish were among the vertebrates of Ordovician Missouri.
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They possess spicules ranging from 23-30 μm in length and cup-shaped buccal capsules (mouths) that open at the anterior end. Located deep in the buccal cavity are eight to 10 teeth that are not thought to be used for attachment. The adult male is about half the length of the female. Case reports have found male worms ranging from 3–6.3 mm in length and 360-380 μm in width.
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G. neoplasticum completes its life cycle in two hosts, rats as definitive hosts, and cockroaches (Periplaneta) as intermediate hosts. It is hermaphrodite, and has both male and female reproductive organs in the same body. The male reproductive system consists of a single testis, vas deferens, seminal vesicles, ejaculatory duct, two spicules, gubernaculum and bursa. Female reproductive organs include a pair of ovaries, oviducts, seminal receptacle, uteri and a long oviduct, vagina and vulva.
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They are usually found amongst seaweed in temperate seas, but they are probably widely distributed; some are fresh-water. The genus Chaetosoma, with the two species Ch. claparedii and Ch. ophicephalum and the genus Tristicochaeta, have swollen heads. The third genus Rhabdogaster has no such distinct head, though the body may be swollen anteriorly. The mouth is terminal and anterior and surrounded by a ring of spicules or a half-ring of hooks.
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Glass sponges present a distinctive variation on this basic plan. Their spicules, which are made of silica, form a scaffolding-like framework between whose rods the living tissue is suspended like a cobweb that contains most of the cell types. This tissue is a syncytium that in some ways behaves like many cells that share a single external membrane, and in others like a single cell with multiple nuclei. The mesohyl is absent or minimal.
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It accumulates more rapidly than any other pelagic sediment type, with a rate that varies from 0.3–5 cm/1000 yr. Siliceous ooze is ooze that is composed of at least 30% of the siliceous microscopic "shells" of plankton, such as diatoms and radiolaria. Siliceous oozes often contain lesser proportions of either sponge spicules, silicoflagellates or both. This type of ooze accumulates on the ocean floor at depths below the carbonate compensation depth.
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E. godeffroyi E. godeffroyi is nocturnal and is a deposit feeder. It spends the day hidden among the rubble and corals. It emerges at night, crawling along using its anchor spicules for adhesion, and extending its tentacles onto the sediment which sticks to them; food particles are passed to the mouth where they are scraped off. The sea cucumber selects the more nutritious particles it finds and consumes several times its bodyweight each day.
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The starfish has plates on its aboral (upper) surface arranged in a reticulate fashion with brightly coloured tubercles scattered between them. There are only a few inconspicuous marginal plates but the superomarginal plate at the end of each arm is very large. The tube feet are tipped with suckers and do not have any spicules. The tubercles vary in size and colour, making a red, purple and orange pattern on the aboral surface.
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Freeth, S.J.; C.O. Ofoegbu; and K.M. Onuoha (1992). Natural Hazards in West and Central Africa, pp. 50—51. It feeds on tiny organisms such as rotifers, diatoms and sponge spicules, and organic debris. The specific name honours the entomologist Gerhard Steinbach (1923-2016) of the Humboldt University of Berlin who was a member of an expedition which was led by zoologist Martin Eisentraut on which the type of this cichlid was collected.
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Hexactinosan sponges have a rigid scaffolding of "fused" spicules that persists after the death of the sponge. Other sponge species abundant on sponge reefs are members of the order Lyssactinosa (Rosselid sponges) and include Rhabdocalyptus dawsoni (boot sponge), Acanthascus platei, Acanthascus cactus and Staurocalyptus dowlingi. Rosselid sponges have a "woven" or "loose" siliceous skeleton that does not persist after the death of the sponge, and are capable of forming mats, but not reefs.
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Halichondria is a genus of sea sponges belonging to the family Halichondriidae.A systematic revision of the central West Atlantic: Halichondrida (Demospongiae, Porifera). Part III: Description of valid species These are massive, amorphous sponges with clearly separated inner and outer skeletons consisting of bundles of spicules arranged in a seemingly random pattern. This genus of sponges became important through the discovery of cell division limiting properties of the extract Halichondrin B, which inhibits cell mitosis.
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The curve of the spatula also has a grouping of spicules rimming its edges. Like other members of Haidomyrmecini the mandibles of Ceratomyrmex are modified into elongated scythe like shapes. The mandibles are enlarged to reach over the head to the apex of the horn creating a trap-jaw. Near the point where the closed mandibles rest, four very long trigger hairs are placed, with two on each side of the head.
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There are a small number of large oscules, mostly towards the top of the sponge.European Marine LifeMarine Life Information Network On microscopic examination it can be seen that the megascleres are in two sizes, one twice as large as the other. There are very few microscleres, and these are one tenth of the size of the megascleres. The skeleton is composed of spicules arranged radially near the surface, but chaotically in the interior.
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The male can inseminate the hermaphrodite, which will preferentially use male sperm (both types of sperm are stored in the spermatheca). Once he recognizes a hermaphrodite worm, the male nematode begins tracing the hermaphrodite with his tail until he reaches the vulval region. The male then probes the region with his spicules to locate the vulva, inserts them, and releases sperm. The sperm of C. elegans is amoeboid, lacking flagella and acrosomes.
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Spicules last for about 15 minutes; at the solar limb they appear elongated (if seen on the disk, they are known as "mottles" or "fibrils"). They are usually associated with regions of high magnetic flux; their mass flux is about 100 times that of the solar wind. They rise at a rate of 20 km/s (or 72,000 km/h) and can reach several thousand kilometers in height before collapsing and fading away.
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There are three kinds of spicules: regular triradiates, quadriradiates and very slender, hair-like oxea. The regular triradiates have rather stout, slightly fusiform rays, bluntly and rather abruptly pointed at the apex, which is often somewhat irregular. The rays measure about 0.1 mm in length by 0.012 mm in diameter at the thickest part. The quadriradiates are abundant and resemble the triradiates, but with an apical ray projecting at right angles into the gastral cavity.
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Rasheedia heptacanthi is a parasitic nematode in the genus Rasheedia. The species is an intestinal parasite of the Cinnabar goatfish Parupeneus heptacanthus (Mullidae) and Dentex fourmanoiri (Sparidae) off New Caledonia. The two species Rasheedia heptacanthi and Rasheedia novaecaledoniensis, which both occur in New Caledonian waters, are mainly differentiated by the number of anterior protrusible oesophageal lobes (two in R. heptacanthi and four in R. novaecaledoniensis), structure of the oesophagus and the lengths of their spicules.
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They extend respiratory trees from their cloaca in order to breathe. Their body wall is thick, making up a total of 56% of their weight. This body wall is filled with calcareous plates called spicules, and are used to ID species; the sandfish is identified by table and knobbed button shapes. Like other sea cucumbers, they can eviscerate their internal organs if they undergo stress, and can regenerate their organs; in sandfish this takes about 2 months.
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Measuring 2 and 7 mm in length alive, the two animals found were creamy white in colour. The mantle surface is smooth with minute spicules projecting and scattered small white spots which probably mark the position of glands. The pinkish viscera can be seen through the semi- translucent mantle. There are nine cream coloured glands on each side on the 7 mm animal; with five on one side, six on the other of the 2 mm specimen.
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Oscarella carmela is either encrusting or massive and forms a slimy covering or a thicker layer of spongy matter with an uneven, lumpy, lobed surface. It grows in patches on hard substrates up to in diameter and overgrows other organisms. The colour is variable and ranges from orange-brown to tan or beige. This sponge does not contain spicules or spongin to reinforce its body wall and has a simple structure with only two types of cell with inclusions.
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Pikaia, discovered much earlier but from the Mid Cambrian Burgess Shale, is also regarded as a primitive chordate. On the other hand, fossils of early chordates are very rare, as non-vertebrate chordates have no bone tissue or teeth, and fossils of no Post-Cambrian non-vertebrate chordates are known aside from the Permian-aged Paleobranchiostoma, trace fossils of the Ordovician colonial tunicate Catellocaula, and various Jurassic-aged and Tertiary-aged spicules tentatively attributed to ascidians.
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The mouth opens into an oesophagus which passes into an intestine; this opens by a ventral anus situated a little in front of the posterior end. The testis is single, and its duct opens with the anus, and is provided with a couple of spicules. The ovary is double, and the oviducts open by a median ventral pore about the middle of the body; in this region there is a second swelling. both in Chaetosoma and in Rhabdogaster.
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In the anterior part of the visceral hump, the heart bulb is visible externally on the right side of the body. A few elongate, subepidermal spicules of up to 40 μm in length can be found in the posterior part of the visceral hump. Organ complexity as seen in Pseudunela cornuta (regarding excretory and reproductive features, at least) represents innovations that evolved in small, mesopsammic marine acochlidians. nervous system of Pseudunela cornuta shows ganglia and their interconnections with nerves.
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A chemical compound called "jorumycin" has been found in a related species, Jorunna funebris. This compound is a tetrahydroisoquinoline, meaning it contains the same basic chemical backbone as an antitumor drug called PM00104, or Zalypsis, which is meant to be injected intravenously. Sea bunnies are considered to be one of 16 species in the family Discodorididae. The fur is called caryophyllidae, which is composed of fleshy protuberances called papillae, as well as spicules, which are used for sensory functions.
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Chondrocladia lampadiglobus A few species that live in waters where the supply of food particles is very poor prey on crustaceans and other small animals. So far only 137 species have been discovered. Most belong to the family Cladorhizidae, but a few members of the Guitarridae and Esperiopsidae are also carnivores. In most cases little is known about how they actually capture prey, although some species are thought to use either sticky threads or hooked spicules.
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There have been observations of large solitary species (up to a few mm). Three types of skeleton are observed in Collodaria: some species create shell-like skeleton around the central capsule, others form silica spicules or have no mineral structures. The shape of central capsules and density of cytoplasmic vacuoles can vary among species and may serve as a distinguishing taxonomic character such as the separation of the genera Collophidium and Collozoum within the family of Sphaerozoidae.
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During this time, sponges, such as Actinocoelia meandrina, proliferated, only to be buried in lime mud and their internal silica needles (spicules) dissolved and recrystallized to form discontinuous layers of light-colored chert. In the park, this formation can be found in the Hurricane Cliffs above the Kolob Canyons Visitor Center and in an escarpment along Interstate 15 as it skirts the park.Harris 1997, p. 35 This is the same formation that rims the Grand Canyon to the south.
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The sponge also contains a choanosomal skeleton, which consists of a dense, irregular mesh of polygons formed by secondary fibers and primary fibers rise from it. The primary fibers are 50 to 100 nanometers in diameter and are composed of spongin and inclusions such as sand grains and spicules. The secondary fibers are 20 to 35 nanometers in diameter and are composed of only spongin without inclusions. Spongia officinalis is light grey to black in color.
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Lesser fish eagles are fish-eating birds that have feet adapted to aid in gripping slippery fish. They have strongly curved talons, and spicules along the underside of the birds' toes help to grip fish as they pull them from the water. There are two subspecies: Haliaeetus humilis humilis, which is native to the Malaysian Peninsula, Sumatra, Borneo, and Sulawesi; and Haliaeetus humilis plumbeus, which is native to Kashmir through southeast India, Nepal, and Burma towards Indochina.
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It seldom encrusts sea fans. Alcyonium coralloides overgrowing Eunicella singularis In the Mediterranean, the habit of growth of Alcyonium coralloides is often encrusting, growing over the surface of a gorgonian. The sea fan has a rigid skeleton so Alcyonium coralloides does not need a supportive skeleton but it does however have spicules in its surface layers which makes it rough to the touch. The colour of the colony is often purple, but may be white, pink or yellow.
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Pelagic Clays containing iron- manganese micronodules, quartz, plagioclase, orthoclase, magnetite, volcanic glass, montmorillonite, illite, smec- tite, foraminiferal remains, diatoms, and sponge spicules made up the uppermost stratigraphic section at each site it was found at. This sediment type consisted of 4.2 percent of the total thickness of sediment recovered by the Deep Sea Drilling Project (DSDP). Biogenic pelagic silica sediments consist of radiolarian, diatomaceous, silicoflagellate oozes, and chert. It makes up 4.3% of the sediment thickness recovered.
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Males have specialised tails for mating that include spicules. In 1963, Sydney Brenner proposed research into C. elegans, primarily in the area of neuronal development. In 1974, he began research into the molecular and developmental biology of C. elegans, which has since been extensively used as a model organism. It was the first multicellular organism to have its whole genome sequenced, and as of 2019, is the only organism to have its connectome (neuronal "wiring diagram") completed.
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A set of "valve cells" connects the pharynx to the intestine, but how this valve operates is not understood. After digestion, the contents of the intestine are released via the rectum, as is the case with all other nematodes. No direct connection exists between the pharynx and the excretory canal, which functions in the release of liquid urine. Males have a single-lobed gonad, a vas deferens, and a tail specialized for mating, which incorporates spicules.
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Synaptula recta is an elongated sea cucumber growing to a maximum length of about . The mouth is at the anterior end and is surrounded by thirteen feeding tentacles. The colour is variable but it is often a deep colour, ranging from dark reddish-purple to a fairly bright red, olive or a pattern of longitudinal lilac stripes on a pale background. The calcareous spicules in the cuticle consist of anchors with knobbed ends and curved bodies.
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These include: spicules, tail shapes and caudal papillae. This family of parasites have a complex life cycle, meaning that they come in contact with more than one host throughout the duration of their life. Adult Anisakidae worms lay eggs in the gut of many species of marine mammals, and then these eggs are excreted from the host via fecal matter. Once these hatched larvae are in open water, they can be ingested by krill or other crustaceans.
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Limatula hodgsoni is found on the seabed of the waters around Antarctica at depths down to at least . It is very common in the zone deeper than which is the lower limit for anchor ice formation. In some areas, this zone is characterised by a layer of sponge spicules and dead mollusc shells a metre or more thick, overgrown by living sponges. This matrix is a biodiverse habitat rich in sea anemones, polychaete worms, hydroids, bryozoans and molluscs.
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The fossil was discovered in the Woodford Shale, exposed at the Ryan Quarry, in Pontotoc County, Oklahoma. The Woodford Shale is a dark-colored siliceous shale which outcrops to the north- east and the south-west of the Arbuckle Mountains in Oklahoma. It contains "radiolarians, conodonts, sponge spicules, ammonoid and nautiloid cephalopods, inarticulate brachiopods [...] and small phyllocarid arthropods", and spans the Devonian–Carboniferous boundary. The strata which produced Aciculopoda are thought on the basis of conodont biostratigraphy to be from the Famennian.
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Some of them are radially symmetrical, but most are asymmetrical. The shapes of their bodies are adapted for maximal efficiency of water flow through the central cavity, where the water deposits nutrients and then leaves through a hole called the osculum. Many sponges have internal skeletons of spongin and/or spicules (skeletal-like fragments) of calcium carbonate or silicon dioxide. All sponges are sessile aquatic animals, meaning that they attach to an underwater surface and remain fixed in place (i.e.
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A sponge fragment can only regenerate if it contains both collencytes to produce mesohyl and archeocytes to produce all the other cell types. A very few species reproduce by budding. Gemmules are "survival pods" which a few marine sponges and many freshwater species produce by the thousands when dying and which some, mainly freshwater species, regularly produce in autumn. Spongocytes make gemmules by wrapping shells of spongin, often reinforced with spicules, round clusters of archeocytes that are full of nutrients.
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With its vermiform body, a putatively multi-functional radula, ‘simplified’ organ systems and a special fast and imprecise mode of sperm transfer, Pontohedyle reflects a meiofaunal slug lineage highly adapted to its interstitial habitat. Pontohedyle is morphologically well-defined genus of meiofaunal slugs. Specimens of Pontohedyle are externally uniform and easily distinguishable from other acochlids by the lack of rhinophores and the bow- shaped oral tentacles. Pontohedyle typically bear monaxone, rodlet-like spicules distributed randomly and frequently accumulated between the oral tentacles.
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In the Haeckel's work, Collodaria was named the first order of Radiolaria, and defined as “Spumellaria without latticed shell.” This definition of Collodaria was further expanded to include organisms that either completely lack the skeleton or have numerous spicules that loosely scatter throughout the calymma around the central capsule. In recent literature, the definition of Collodaria has been altered with molecular phylogenetic characteristics. In Haeckel's phylogeny, the second order in Radiolaria, Sphaerellaria, includes all Radiolaria with any trace of latticed or fenestrated shell.
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Hexasterophora are a subclass of sponges, in the class Hexactinellida. The Hexasterophora first appeared in the Ordovician and is separated into five recent orders, including the Lyssacinosa, the Hexactinosa, and the Lychniscosa, all of which have living representatives in the seas today. Hexasterophorans have skeletons composed of overlapping six-rayed spicules.Access Science The sponge is commonly firmly attached by its base to a hard substratum; less often rooted by the anchoring spicules and rarely inserted directly into the loose bottom sediments.
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The yellow boring sponge inhabits living bivalve molluscs, boring into the shell valves. The only parts of the sponge which are visible from the outside are small yellow patches up to in diameter, sometimes containing small oscula (openings). The sponge spicules are silicaceous (glassy) and are scattered throughout the sponge tissues. They consist entirely of megascleres known as "tylostyles", which are a kind of spicule with a single shaft, with a point on one end and a knob on the other.
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Such a skeleton is present in echinoderms and chordates. The poriferan 'skeleton' consists of microscopic calcareous or siliceous spicules or a spongin network. The Coleoidae do not have a true endoskeleton in the evolutionary sense; there, a mollusk exoskeleton evolved into several sorts of internal structure, the "cuttlebone" of cuttlefish being the best-known version. Yet they do have cartilaginous tissue in their body, even if it is not mineralized, especially in the head, where it forms a primitive cranium.
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The layer of the chromosphere atop the photosphere is homogeneous. A forest of hairy-appearing spicules rise from the homogeneous layer, some of which extend 10,000 km into the corona above. The density of the chromosphere is only 10−4 times that of the photosphere, the layer beneath, and 10−8 times that of the atmosphere of Earth at sea level. This makes the chromosphere normally invisible and it can be seen only during a total eclipse, where its reddish color is revealed.
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Fibrous dysplasia is a mosaic disease resulting from post- zygotic activating mutations of the GNAS locus at 20q13.2-q13.3, which codes for the α subunit of the Gs G-coupled protein receptor. In bone, constitutive Gsα signaling results in impaired differentiation and proliferation of bone marrow stromal cells. Proliferation of these cells causes replacement of normal bone and marrow with fibrous tissue. The bony trabeculae are abnormally thin and irregular, and often likened to Chinese characters (bony spicules on biopsy).
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Small flat chiton, 15-25mm in length, usually oval with some individuals almost round. Crests of the valves are smooth with radial ribs and granular grooves running down to the edges, the whole usually light greenish with darker blotches. The yellowish brown girdle is relatively wide and is covered in spicules. There are tufts of white bristles along the inner girdle at the base of each valve suture and at the head, with shorter bristles surrounding the margin poking outwards.
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Arturia canariensis has a small, lacy structure and is a bright lemon yellow colour. It is an asconoid with many tiny flask-like tubes. Water is drawn in through fine holes near their base, the ostia, moved along by flagella and expelled from the oscula at the top, each osculum being a single exit formed from many fused ascon tubes. The skeleton is composed of large calcareous spicules called megascleres, made predominantly of calcite, forming a soft, fragile, supporting network.
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There is still debate in the scientific community as to why plants form phytoliths, and whether silica should be considered an essential nutrient for plants. Studies that have grown plants in silica-free environments have typically found that plants lacking silica in the environment do not grow well. For example, the stems of certain plants will collapse when grown in soil lacking silica. In many cases, phytoliths appear to lend structure and support to the plant, much like the spicules in sponges and leather corals.
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Plant fossils include pollen, spores, logs, and other plant macrofossils. Invertebrate fossils include foraminifera (protists that form test shells), sponge spicules, bryozoans, bivalves, gastropods, Spirorbis, beetles, ants, barnacles, decapod crustaceans (crabs, shrimp, lobsters, etc.), ostracodes (seed shrimp), and ophiuroids (brittle stars). Vertebrate fossils include fish and a few rare large mammals, such as walruses, whales, and a mammoth. Walrus remains have been reported on Andrews Island, west of Isle au Haut; Addison Point, northeast of the Schoodic Peninsula; and Gardiner, west-northwest of Isle au Haut.
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In (d) the RBCs are rendered crenated from a hypertonic solution Crenation is also used to describe a feature of red blood cells. These erythrocytes look as if they have projections extending from a smaller central area, like a spiked ball. The crenations may be either large, irregular spicules of acanthocytes, or smaller, more numerous, regularly irregular projections of echinocytes. Acanthocytes and echinocytes may arise from abnormalities of the cell membrane lipids or proteins, or from other disease processes, or as an ex vivo artifact.
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Facial masks and adhesive tapes removed about 40% and 30% of the spines, respectively, and produced more retention and inflammation three days after removal than no treatment. Repeated applications of adhesive tape did not improve the results. According to Martinez, the most effective method is to first use tweezers to remove clumps of spines followed by the application and removal of household glue, resulting in removal of 95% of the spines. Unroofing the early vesicles or pustules may permit manual extraction of the spicules.
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Cucullanus austropacificus, scanning electron microscopy Cucullanus austropacificus is a species of parasitic nematodes. It is an endoparasite of the fish Conger cinereus. The species has been described in 2018 by František Moravec & Jean-Lou Justine from material collected off New Caledonia in the South Pacific Ocean. Cucullanus austropacificus was characterized by the following morphological features: presence of cervical alae, ventral sucker, alate spicules 1.30–1.65 mm long, conspicuous outgrowths of the anterior and posterior cloacal lips and elongate-oval eggs measuring 89–108 × 48–57 μm.
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The calcium carbonate or silica spicules of most sponge genera make them too rough for most uses, but two genera, Hippospongia and Spongia, have soft, entirely fibrous skeletons. Early Europeans used soft sponges for many purposes, including padding for helmets, portable drinking utensils and municipal water filters. Until the invention of synthetic sponges, they were used as cleaning tools, applicators for paints and ceramic glazes and discreet contraceptives. However, by the mid-20th century, over-fishing brought both the animals and the industry close to extinction.
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Oscarella lobularis is an encrusting sponge that forms a thick layer of soft, gelatinous consistency with a velvety surface, on rocks, stones and large seaweeds. Colonies are up to wide and thick, with an irregularly lobed surface. The sides of the nodular lobes have a scattering of ostia through which water passes into the sponge, and at the top of each, a single round osculum up to in diameter, through which water exits. This sponge has neither spicules nor spongin fibres in its tissues.
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Dichelyne alatae is a species of nematode, described on the basis of the worms recovered from the intestine of the whiting, Sillaginopsis panijus from the estuary of the Hooghly River at Kalyani, West Bengal, India. Dichelyne alatae is unique in having a small body size, deirids posterior to the oesophagus, short and wide caudal alae at the level of cloacal opening, unequal, alate spicules, a shield-shaped gubernaculum, a different number of caudal papillae and a conical tail with spines in its distal region.
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These colonies adopt a range of massive, branching, leaf-like and encrusting forms. Soft corals in the subclass Octocorallia are also colonial and have a skeleton formed of mesogloeal tissue, often reinforced with calcareous spicules or horny material, and some have rod-like supports internally. Other anthozoans, such as sea anemones, are naked; these rely on a hydrostatic skeleton for support. Some of these species have a sticky epidermis to which sand grains and shell fragments adhere, and zoanthids incorporate these substances into their mesogloea.
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The girdle is often ornamented with spicules, bristles, hairy tufts, spikes, or snake-like scales. The majority of the body is a snail-like foot, but no head or other soft parts beyond the girdle are visible from the dorsal side. The mantle cavity consists of a narrow channel on each side, lying between the body and the girdle. Water enters the cavity through openings in either side of the mouth, then flows along the channel to a second, exhalant, opening close to the anus.animalnetwork.
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Goniodoridella savignyi is species of sea slug, specifically a dorid nudibranch, a marine gastropod mollusc in the family Goniodorididae. This nudibranch has a wide distribution and can be found throughout the tropical and subtropical Indo-West Pacific with sightings in Australia, Papua New Guinea, Indonesia, the Yellow Sea, the Japan Sea, the Red Sea and South Africa. Its color is white with variable amounts of bright yellow dots on top of the spicules. In some specimens, it has shown brownish pigments instead of yellow pigments.
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In 1899 he succeeded Raphael Weldon as Jodrell Professor of Zoology and Comparative Anatomy, and curator of what is now the Grant Museum of Zoology at University College London (UCL). While Professor of Zoology at UCL Minchin worked on sponges, especially the development of spicules in calcareous sponges. He was the first to conclusively prove that sponges are not part of the Coelenterata. Lankester had long lobbied for a permanent Chair of Protozoology at the University of London and in 1906 the position was finally created, associated with the Lister Institute of Preventive Medicine.
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Colochirus robustus, commonly known as the robust sea cucumber or the yellow sea cucumber, is a species of sea cucumber in the family Cucumariidae. It is found in shallow seas in tropical parts of the central Indo-Pacific region. C. robustus belongs to the class Holothuroidea, a group of echinoderms called sea cucumbers and known for unusual behavior including evisceration, asexual reproduction, and regeneration. The robust sea cucumber has a soft body and lacks a spine, but it does have an endoskeleton consisting of microscopic spicules, or ossicles, made of calcium carbonate.
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S. maculata is a long, slender sea cucumber with fifteen tentacles, growing to a length of about . Although not the heaviest or bulkiest sea cucumber in the world, it is probably the longest, with individuals exceptionally reaching to over . Its colouring is variable, being some shade of yellowish-brown with wide longitudinal stripes and patches of darker colour. The spicules (microscopic calcareous spike-like structures that support the body wall) are large and shaped like anchors and are used in locomotion; they can be as long as 2 mm.
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Strubellia species are reddish-brown, slender slugs of 5 to 40 mm length. They live under rocks in streams and creeks on volcanic islands and feed on the contents of calcareous egg capsules of other, herbivorous, snails (family Neritidae) occurring in the same habitat. Their radula is modified for slowly piercing these capsules with a sharp, saw-like central teeth of which some are worn down during the process. Calcareous spicules embedded below the skin help to stabilize the head during feeding; the nutritive contents of the capsules are slowly sucked out.
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Homaxinella was originally included in the sponge family Axinellidae but the structure of the skeleton shows that it lacks a reticulation and has bundles of calcareous spicules at the surface which led to its inclusion in Suberitidae. The members of the genus are rooted to the substrate and have stalks, a much branched habit of growth and an axially condensed choanosomal skeleton. They have an extra-axial skeleton of bundles of megascleres which are exclusively styles, and a profusion of further incoherently arranged styles, in a wide range of sizes. There are no microscleres.
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Many predators find the spicules of Homaxinella balfourensis distasteful but the sea stars Odontaster meridionalis and Odontaster validus feed on it, leaving behind the spongin which provides a fibrous support to the sponge. Small copepods in the family Arcturidae are often to be found among the sponge's branches. Homaxinella balfourensis often grows on the upper valve of the Antarctic scallop (Adamussium colbecki) when these shells reach a length of at last , usually being attached near the shell margin where the sponge may benefit from an increased flow of water.
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Other components of siliceous oozes near continental margins may include terrestrially derived silica particles and sponge spicules. Siliceous oozes are composed of skeletons made from opal silica Si(O2), as opposed to calcareous oozes, which are made from skeletons of calcium carbonate organisms (i.e. coccolithophores). Silica (Si) is a bioessential element and is efficiently recycled in the marine environment through the silica cycle. Distance from land masses, water depth and ocean fertility are all factors that affect the opal silica content in seawater and the presence of siliceous oozes.
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Hemipenes can be found in a variety of shapes and sizes, but foundationally, have same general structure. They are made up of two hemipenises tucked under the tail side by side, with each of the lobes exhibiting a range of ornamentation, including spicules and hooks. Hemipenes also have an outer groove called the sulcus spermaticus, which transports sperm through the outside, rather than the inside, of the organ. This is structurally different from the human penis, which has sperm travel inside the organ through the vas deferens and the urethra.
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Cucullanus gymnothoracis, scanning electron microscopy Cucullanus gymnothoracis is a species of parasitic nematodes. It is an endoparasite of the lipspot moray Gymnothorax chilospilus. The species has been described in 2018 by František Moravec & Jean-Lou Justine from material collected off New Caledonia in the South Pacific Ocean. Cucullanus gymnothoracis was considered somewhat similar to Cucullanus austropacificus, but differs from this species in the absence of cervical alae and the posterior cloacal outgrowth, in the shape and size of the anterior cloacal outgrowth and shorter spicules 1.12 mm long.
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Some types of cells have a single nucleus and membrane each, but are connected to other single- nucleus cells and to the main syncytium by "bridges" made of cytoplasm. The sclerocytes that build spicules have multiple nuclei, and in glass sponge larvae they are connected to other tissues by cytoplasm bridges; such connections between sclerocytes have not so far been found in adults, but this may simply reflect the difficulty of investigating such small-scale features. The bridges are controlled by "plugged junctions" that apparently permit some substances to pass while blocking others.
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Freshwater sponges often host green algae as endosymbionts within archaeocytes and other cells, and benefit from nutrients produced by the algae. Many marine species host other photosynthesizing organisms, most commonly cyanobacteria but in some cases dinoflagellates. Symbiotic cyanobacteria may form a third of the total mass of living tissue in some sponges, and some sponges gain 48% to 80% of their energy supply from these micro-organisms. In 2008 a University of Stuttgart team reported that spicules made of silica conduct light into the mesohyl, where the photosynthesizing endosymbionts live.
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Most of the cells transform into archeocytes and then into the types appropriate for their locations in a miniature adult sponge. Glass sponge embryos start by dividing into separate cells, but once 32 cells have formed they rapidly transform into larvae that externally are ovoid with a band of cilia round the middle that they use for movement, but internally have the typical glass sponge structure of spicules with a cobweb- like main syncitium draped around and between them and choanosyncytia with multiple collar bodies in the center. The larvae then leave their parents' bodies.
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The general colour is grey or beige, sometimes tinged with pink or purple. The skeleton contains long, slender styles, megascleres with one end pointed and the other end rounded; the blunt end of each has a series of abrupt narrowings which gives a stepped effect. Some of these megascleres are scattered throughout the mesogloea while others are formed into wispy bundles supporting the surface of the sponge. Hymeniacidon kitchingi could be confused with Halichondria bowerbanki, but that species has longer, more slender lobes and a different range of spicules.
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They also observed the surface projections as on IBV, stating, "The outer surface of the particle is covered by 'spicules'." Transmission electron microscopic images of coronaviruses 229E (2), B814 (3) and IBV (4) In 1966, Tyrrell sought the help of Anthony Peter Waterson at the St Thomas's Hospital Medical School in London who had recruited June Dalziel Almeida as an electron microscopist. Almeida had studied IBV and MHV finding them as structurally distinct viruses, but her manuscript was rejected upon a referee's decision that the microscopic images were of influenza virus and lacked novelty.
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After I left, he soon had it working properly. He obtained daily records of the spectrum of the corona, which furnished us with a valuable index of solar activity. At Climax, Walter Roberts quickly proved observationally what most astronomers had previously suspected, that the corona itself rotated with the same period as the solar surface, in something over twenty-five days. He initiated a study of the fine structure of the solar atmosphere, determining the behavior of what he called “spicules,” a phenomenon that I had myself briefly discussed while at Lick Observatory.
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In several groups of Nudibranchia, eyes can be located toward the bottom of these rhinophores which can entail possible homology of related ancestors. In internal organs, developing from the stomach is the intestine composing of a thick fold of tissue termed typhlosole which is plesiomorphic to Nudibranchia. In the superfamily Aeolidioidea, the typhlosole is present. The function of the typhlosole has not been determined, in some clades, it is possible that it aids in a secretion to help excretion of wastes or provides support in digestion of hard structures like sponge spicules.
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Shelley and Arthur had verified the depth by injecting individual itch powder spicules (Mucuna pruriens), and found that maximal sensitivity was found at the basal cell layer or the innermost layer of the epidermis. Surgical removal of those skin layers removed the ability for a patient to perceive itch. Itch is never felt in muscle or joints, which strongly suggests that deep tissue probably does not contain itch signaling apparatuses. Sensitivity to pruritic stimuli is evenly distributed across the skin, and has a clear spot distribution with similar density to that of pain.
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The Great Eruptive Solar Prominence of June 4, 1946 Dr. Bernard Lyot developed the first coronagraph to study the Sun's corona. Improved coronagraphs are used at the High Altitude Observatory by Dr. Walter Roberts and at the Evans Solar Facility by Dr. J. W. Evans. Dr. Donald H. Menzel was the first to use the coronagraph in America. These coronagraphs are used to film structures on the Sun called prominences and spicules which show matter flowing on the surface in structures many times the size of the Earth.
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Their large prey is not swallowed immediately, instead being butchered at a perch or nest site outside the breeding season. osprey with catch at Peel Harvey Estuary The genus Pandion has several adaptations that suit its piscivorous lifestyle, these include reversible outer toes, sharp spicules on the underside of the toes, closable nostrils to keep out water during dives, and backwards-facing scales on the talons which act as barbs to help hold its catch. The osprey has dense plumage which is oily and prevents its feathers from getting waterlogged.
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If a sponge contains spicules along with organic compounds, the likelihood of those sponges being consumed by spongivores decrease. Sponges have also developed aposematism to help avoid predation. Spongivores have learned four things about sponges aposematism and they are as follows: # If it is poison some predators will not eat it # If It is conspicuously coloured, or advertises itself by means of some other signals; # Some predators avoid attacking it because of its signals # These conspicuous signals provide better protection to the individual or to its genes than would other (e.g. cryptic) signals.
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Sclerites generally form within the cuticle, protruding through when they are fully grown. They probably start life as amorphous calcium carbonate, which the organic matrix coaxes into an aragonitic habit as the spines mature. Sclerites can be shaped as simple spines, straight, curved, keeled, striated or hooked; or as cupped blades; more complex arrangements are common in copulatory spicules. In several species of solenogaster, sclerites change morphology during growth; young specimens might bear flat, solid, scale-like sclerites, to be replaced with longer hollow spine-like sclerites in adults.
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Series definition within this subgenus is based on the cibarial armature - a collection of specialized spicules borne ventrally at the posterior margin of the cibarium - which was first used as a taxonomic method by Christophers in 1933. Kerteszia is a small subgenus found in South America whose larvae have specific ecological requirements; these can only develop within water that accumulates at the base of the follicular axis of the epiphytic Bromeliaceae. Unlike the majority of mosquitoes, species in this subgenus are active during the day. Within a number of species, separate subspecies have been identified.
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Clathrina clathrus is a species of calcareous sponge belonging to the family Clathrinidae. This yellow (occasionally white) sponge, up to 10 cm in diameter, usually appears cushion-shaped at a distance (its close relative Clathrina coriacea is normally flatter in appearance). Close-up the sponge can be seen to consist of a tangled mass of tubes (these tubes are thicker and less tightly knit than in C. coriacea and there is no osculum as found in that species). Like C. coriacea, the spicules are exclusively three-pointed triactines.
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Members of the family Holothuriidae have thick fleshy bodies and several rows of tube feet which are used for moving around and for adhering to the surface. The body is often covered with blunt projections known as papillae. Many of the members of this family are able to eject a mass of fine sticky threads known as cuvierian tubules to distract predators, or even turn their viscera inside out.Saltwater Aquariums For the taxonomic determination, the genera Actinopyga and Bohadschia have their spicules exclusively shaped like sticks, and the genera Holothuria and Labidodemas never have theirs shaped like tables.
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Holes made by clionaid sponge (producing the trace Entobia) after the death of a modern bivalve shell of species Mercenaria mercenaria, from North Carolina Close-up of the sponge boring Entobia in a modern oyster valve. Note the chambers which are connected by short tunnels. Many sponges shed spicules, forming a dense carpet several meters deep that keeps away echinoderms which would otherwise prey on the sponges. They also produce toxins that prevent other sessile organisms such as bryozoans or sea squirts from growing on or near them, making sponges very effective competitors for living space.
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No diagnostic differences in external morphology or spicules could be detected between the collected populations apart from eyes externally visible or not. Comparative SEM-examination of the available radulae revealed two types of the typically hook-shaped radula: a lateral tooth without a denticle (Pontohedyle verrucosa) or with a denticle (Pontohedyle milaschewitchii). Pontohedyle slugs have a well-adapted body plan that can be conserved for millions of years in a worldwide evolutionary success story. Pontohedyle presents a stunning example of extreme morphological stasis and uniformity over long evolutionary timeframes, probably constrained by their simplified bodyplan and by the requirements of the meiofaunal habitat.
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Nilas in Baffin Bay New ice is a general term used for recently frozen sea water that does not yet make up solid ice. It may consist of frazil ice (plates or spicules of ice suspended in water), slush (water saturated snow), or shuga (spongy white ice lumps a few centimeters across). Other terms, such as grease ice and pancake ice, are used for ice crystal accumulations under the action of wind and waves. When sea ice begins to form on a beach with a light swell, ice eggs up to the size of a football can be created.
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Thus, a much greater understanding of the Corona and improvement in the knowledge of the Sun's subtle influence on the Earth's upper atmosphere can be expected henceforth. The Atmospheric Imaging Assembly on NASA's recently launched Solar Dynamics Observatory and NASA's Focal Plane Package for the Solar Optical Telescope on the Japanese Hinode satellite which was used to test this hypothesis. The high spatial and temporal resolutions of the newer instruments reveal this coronal mass supply. These observations reveal a one-to-one connection between plasma that is heated to millions of degrees and the spicules that insert this plasma into the corona.
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Sigmoilinopsis is a genus of miliolid Foraminifera, with an ovate test, chambers one-half coil in length, arranged in rapidly changing planes in the early stage resulting in two spiralling series that appear sigmoid in section, gradually becoming planispiral in the adult. Walls are thick, porcelaneous but enclosing a large quantity of agglutinated quartz particles, sponge spicules, and shell fragments; the aperture terminal, rounded, with a small tooth. Sigmoilinopsis is grossly similar to Sigmoilina but with less enveloping chambers allowing earlier ones to be externally visible, and in incorporating agglutinated material. Sigmoilinopsis is included in the Hauerinidae (Loeblich & Tappan 1988).
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Pope 2004, p.47-48 The Aleman Formation has up to 70% chert, in the form of thin continuous beds of sponge spicules within calcisiltite beds or of diagenetic lenses of chert nodules within skeletal wackestone or packstone. The continuous chert beds appear to have been laid down in cool water, while the packstone was deposited in warmer water.Pope 2004, p.48-51 The Cutter Formation is mostly bioturbated tidal flat carbonate mudstone or dolomite.Pope 2004, p.51-52 The contact with the underlying El Paso Formation is an unconformity corresponding to a hiatus of about 30 million years.
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The disease is characterized by flesh-colored to erythematous (reddened) papules occurring in the central region of the face and sometimes elsewhere on the body, often accompanied by protrusive "spicules" or spines made of keratin and by alopecia of affected skin, typically the eyebrows and sometimes the eyelashes or scalp hairs. Pruritus (itching) has been described in about a third of reported cases. Facial papules are generally 1- to 3-mm in size. The condition is considered to be benign, but can be disfiguring; the spines are often prominent, and in later stages the affected facial skin thickens noticeably.
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Mouth and teeth of A. caninum A. caninum egg A. caninum females are typically long and wide, while the males are smaller at in length and in width. Males have a copulatory bursa , which consists of spine-like spicules positioned on three muscular rays that grasp the female during mating. As with other nematodes, the sperm lack flagella. The copulatory bursa is a unique feature of Strongylida members, thus making it a useful means for identifying members of this suborder; it is also used to distinguish members within the suborder due to differences in bursa appearance between species.
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Mermithids are wire-like and have a smooth cuticle with layers of spiral fibres. The digestive tract is similar to that of free-living nematodes only in the young larvae prior to their parasitic life; in the parasitic stages the oesophagus is disconnected from the mid-intestine, and females lack an anus. The female genital opening is at the midbody, while the male opening is at the tip and visible as one or two spicules. The eggs are laid either in water or on land, and the newly hatched larvae are free-living, as are the adults that emerge from the hosts to lay eggs.
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Baerida is an order of sea sponges in the subclass of Calcaronea, first described in 2000 by Radovan Borojevic, Nicole Boury-Esnault and Jean Vacelet. Species of the order Baerida are leuconoid calcareous sponges with the skeleton either composed exclusively of micro-diactines, or in which microdiactines constitute exclusively or predominantly a specific sector of the skeleton, such as choano-skeleton or atrial skeleton. Large or giant spicules are frequently present in the cortical skeleton, from which they can partially or fully invade the choanoderm. In sponges with a reinforced cortex, the inhalant pores can be restricted to a sieve-like ostia-bearing region.
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Bart De Pontieu (Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, California, United States), Robert Erdélyi and Stewart James (both from the University of Sheffield, United Kingdom) hypothesised in 2004 that spicules formed as a result of P-mode oscillations in the Sun's surface, sound waves with a period of about five minutes that causes the Sun's surface to rise and fall at several hundred meters per second (see helioseismology). Magnetic flux tubes that tilted away from the vertical can focus and guide the rising material up into the solar atmosphere to form a spicule. There is still however some controversy about the issue in the solar physics community.
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But nowhere near this level is observed. What happens at the limb is that there is a forest of spicules poking out from the edge, so it is not possible to get parallel to such a rough surface. For most of the solar disk the degree of linear polarization of the continuum is under 0.1%, but it rises to 1% at the limb. The polarization also depends strongly on the wavelength, and for near ultraviolet 3000 Å the light near the limb is 100 times more polarized than red light at 7000 Å. At the limit of the Balmer series a change happens where at shorter wavelengths more bound-bound Balmer series transitions cause more opacity.
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In addition to multiple specimens of fish caught while swordfishing, he collected sponges and bryozoans, many of which were newly-identified species. The best known case was the discovery, during dredging operations carried out in 1909 off the coast of the island of Porto Santo, of an encrusting sponge with limestone and siliceous spicules, which was given the name Merlia normani. These dredging operations were done in conjunction with British spongiologist Randolph Kirkpatrick, who published the description of M. normani.R. Kirkpatrick, "On Merlia normani, a Sponge with a Siliceous and Calcareous Skeleton" in Quarterly journal of microscopical science, n.º 224 (June, 1911), pp. 657-702. Kirkpatrick dedicated a sponge genus to Noronha in 1908,Kirkpatrick, R. (1908).
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Detail of head of a Steller's sea eagle in the Cincinnati Zoo, United States Close-up of talons with hooked sharp claws As in most Haliaeetus eagles, the tarsus and tail are relatively short compared with other very large eagles at and in length, respectively, the Philippine eagle surpassing it by up to and apparently.Brown, Leslie and Amadon, Dean (1986) Eagles, Hawks and Falcons of the World. The Wellfleet Press. . In all sea and fish eagles, the toes are relatively short and stout, with the bottom of the foot covered in spicules and the talons being relatively shorter and more strongly curved than in comparably sized eagles of forests and fields, such as the "booted eagle" group (i.e.
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Uprooted sea pen with the bulbous peduncle in view Pierre's armina feeding on purple sea pen Sea pen at Vancouver Aquarium As octocorals, sea pens are colonial animals with multiple polyps (which look somewhat like miniature sea anemones), each with eight tentacles. Unlike other octocorals, however, a sea pen's polyps are specialized to specific functions: a single polyp develops into a rigid, erect stalk (the rachis) and loses its tentacles, forming a bulbous "root" or peduncle at its base. The other polyps branch out from this central stalk, forming water intake structures (siphonozooids), feeding structures (autozooids) with nematocysts, and reproductive structures. The entire colony is fortified by calcium carbonate in the form of spicules and a central axial rod.
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Originally the members of the family Gorgoniidae included a much wider range of genera than it does now and was used for all of the horny Octocorallia. Now it is restricted to those species where the "calcareous spicules are less than 0.3 mm. in length, sculptured with regularly disposed girdles of complicated tubercles ('warts'), the anthocodiae are relatively unarmed, at most with but a few characteristically shaped flat rods en chevron beneath each tentacle, the horny axial cylinder is weakly loculated if at all, and is perforated by a relatively narrow, chambered central chord, and in which the branchlets are usually quite slender, with a thin cortex."Zoogeography and Evolution in the Octocorralian family Gorgoniidae Frederick M. Bayer.
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Active regions are ensembles of loop structures connecting points of opposite magnetic polarity in the photosphere, the so-called coronal loops. They generally distribute in two zones of activity, which are parallel to the solar equator. The average temperature is between two and four million kelvin, while the density goes from 109 to 1010 particles per cm3. Illustration depicting solar prominences and sunspots Active regions involve all the phenomena directly linked to the magnetic field, which occur at different heights above the Sun's surface: sunspots and faculae, occur in the photosphere, spicules, Hα filaments and plages in the chromosphere, prominences in the chromosphere and transition region, and flares and coronal mass ejections happen in the corona and chromosphere.
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The name "ficus" was first used by Pallas in 1766 for Alcyonium ficus but it is unclear exactly which animal he was describing and it is now thought that it may have been an ascidian. Linnaeus in 1767, Esper in 1794 and Lamarck in 1814 also used the name but it was not until Johnston described the spicules as well as the sponge which he named Halichondria ficus in 1842 that it became clear what sponge was being described. Further research needs to be undertaken to clarify the position.Marine Species Identification Portal Suberites suberia was at one time thought to be a synonym but molecular analysis has shown that it is a distinct species.
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The plattenkalk is formed by layers of packstone and grainstone measuring thick, which alternate with layers of mudstone, wackestone, and marl; the upper bed is also characterized by the presence of sponge spicules, chert, bitumen, and coprolites. On the basis of foraminiferans, the Pietaroia locality has been dated to the Albian epoch of the Early Cretaceous. During this time, the plattenkalk of Pietraroia would have been laid down in a shallow water carbonate platform close to a small island. The depositional environment was originally thought to have been a lagoon, but it has been re-interpreted as an east-flowing underwater channel that was gradually filled during the Aptian, based on patterns in the arrangement of fossils, the water currents, and the transportation of sediments.
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The bony core of the beak is a lightweight framework, like that seen on this alt=an owl's skull with the beak attached Although beaks vary significantly in size and shape from species to species, their underlying structures have a similar pattern. All beaks are composed of two jaws, generally known as the upper mandible (or maxilla) and lower mandible (or mandible). The upper, and in some cases the lower, mandibles are strengthened internally by a complex three- dimensional network of bony spicules (or trabeculae) seated in soft connective tissue and surrounded by the hard outer layers of the beak. The avian jaw apparatus is made up of two units: one four-bar linkage mechanism and one five-bar linkage mechanism.
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Fishing oysters at Emsworth was subsequently halted until new sewers were dug, though the industry never completely recovered. Recently, Emsworth's last remaining oyster boat, The Terror, was restored and is now sailing again. But the oyster industry is again under threat, because the reproductive rate of the oysters has plunged, as they now contain microscopic glass spicules that are shed into the water from the hulls of the numerous plastic fibreglass boats in Chichester Harbour. A soldier from 101st Light Anti-Aircraft Regiment prepares for D-Day by reading his French handbook at a camp in Emsworth, 29 May 1944 During the Second World War, nearby Thorney Island was used as a Royal Air Force station, playing a role in defence in the Battle of Britain.
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Additionally, the mantle edge ofHallaxa chani is semi-translucent and blends in almost seamlessly when spread out on the surface of Halisarca sp. The radular teeth of Hallaxa chani are similar in shape to those of other nudibranchs known to prey primarily on sponges that lack spicules and provided an early clue that Hallaxa chani does not feed on colonial ascidians as originally reported by McDonald & Nybakken (1978) (Goddard, 1981). As noted by Nybakken & McDonald (1981), nudibranchs that specialize on ascidians or fleshy ctenostome bryozoans have a radula dominated by large, paired, wing-shaped lateral teeth. Dorids specializing on dendroceratid and dictyoceratid sponges have thin, comb-like outer lateral teeth with multiple denticles (Goddard, 1981, personal observations; Rudman, 1984; and see electron micrographs of radulae in Gosliner & Johnson, 1994).
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Population density: The subtidal population density of Margarites pupillus in the San Juan Islands, WA, USA, is linked to the abundance of kelp, primarily Agarum fimbriatum. Densities of over 400 snails per square meter can occur where kelp density provides 100% bottom cover, and snail density declines to only a few snails per square meter below the algal zone. Diet: This snail is a generalist grazer; gut contents showed that the digestive tract of all snails examined contained unidentifiable detritus and silt and sand, 94% contained unidentified filamentous red algae, 86% contained diatoms, 79% contained sponge spicules, 64% contained filamentous brown algae, 21% contained remains of hydroids, 14% had remains of bryozoans, and 7% contained filamentous green algae. There was no evidence that M. pupils feeds on Agarum on which it lives.
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Spur cells may refer synonymously to acanthocytes, or may refer in some sources to a specific subset of 'extreme acanthocytes' that have undergone splenic modification whereby additional cell membrane loss has blunted the spicules and the cells have become spherocytic ('spheroacanthocyte'), as seen in some patients with severe liver disease.Mentzer WC. Spiculated cells (echinocytes and acanthocytes) and target cells. UpToDate (release: 20.12- C21.4) Acanthocytosis can refer generally to the presence of this type of crenated red blood cell, such as may be found in severe cirrhosis or pancreatitis, but can refer specifically to abetalipoproteinemia, a clinical condition with acanthocytic red blood cells, neurologic problems and steatorrhea. This particular cause of acanthocytosis (also known as abetalipoproteinemia, apolipoprotein B deficiency, and Bassen-Kornzweig syndrome) is a rare, genetically inherited, autosomal recessive condition due to the inability to fully digest dietary fats in the intestines as a result of various mutations of the microsomal triglyceride transfer protein (MTTP) gene.
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It is difficult to reconstruct the early stages in the evolutionary "family tree" of animals using only morphology (their shapes and structures), because the large differences between Porifera (sponges), Cnidaria plus Ctenophora (comb jellies), Placozoa and Bilateria (all the more complex animals) make comparisons difficult. Hence reconstructions now rely largely or entirely on molecular phylogenetics, which groups organisms according to similarities and differences in their biochemistry, usually in their DNA or RNA. Illustrated tree of cnidarians and their closest relatives It is now generally thought that the Calcarea (sponges with calcium carbonate spicules) are more closely related to Cnidaria, Ctenophora (comb jellies) and Bilateria (all the more complex animals) than they are to the other groups of sponges. In 1866 it was proposed that Cnidaria and Ctenophora were more closely related to each other than to Bilateria and formed a group called Coelenterata ("hollow guts"), because Cnidaria and Ctenophora both rely on the flow of water in and out of a single cavity for feeding, excretion and respiration.
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Vinther and Nielsen (2005) proposed instead that Halkieria was a crown group mollusc, in other words more similar to modern molluscs than to annelids, brachiopods or any intermediate groups. They argued that: Halkieria’s sclerites resembled those of the modern solenogaster aplacophoran shell-less molluscs, of some modern polyplacophoran molluscs, which have several shell plates, and of the Ordovician polyplacophoran Echinochiton; Halkieria’s shells are more similar to the shells of conchiferan molluscs, since shells of both of these groups show no trace of the canals and pores seen in polyplacophoran shell plates; the bristles of brachiopods and annelids are similar to each other but not to Halkieria’s sclerites. However Conway Morris (2006) criticized Vinther and Nielsen's classification of Halkieria as a crown group mollusc, on the grounds that the growth of the spicules in the aplacophorans and polyplacophorans is not similar to the method of growth deduced for the complex halkieriid sclerites; in particular, he said, the hollow spines of various molluscs are not at all like the halkieriid sclerites with their complex internal channels. Conway Morris repeated his earlier conclusion that halkieriids were close to the ancestors of both molluscs and brachiopods.
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Vinther and Nielsen (2005) proposed instead that Halkieria was a crown group mollusc, in other words more similar to modern molluscs that to annelids, brachiopods or any intermediate groups. They argued that: Halkieria’s sclerites resembled those of the modern solenogaster aplacophoran shell-less molluscs (see ), of some modern polyplacophoran molluscs, which have several shell plates, and of the Ordovician polyplacophoran Echinochiton; Halkieria’s shells are more similar to the shells of conchiferan molluscs, since shells of both of these groups show no trace of the canals and pores seen in polyplacophoran shell plates; the bristles of brachiopods and annelids are similar to each other but not to Halkieria’s sclerites. However Conway Morris (2006) criticized Vinther and Nielsen's classification of Halkieria as a crown group mollusc, on the grounds that the growth of the spicules in the aplacophorans and polyplacophorans is not similar to the method of growth deduced for the complex halkieriid sclerites; in particular, he said, the hollow spines of various molluscs are not at all like the halkieriid sclerites with their complex internal channels. Conway Morris repeated his earlier conclusion that halkieriids were close to the ancestors of both molluscs and brachiopods.
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