Well, it's technically called a "pointy-nosed blue ratfish" (hydrolagus trolli), but isn't "ghost shark" so much catchier?
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On inspecting Dr. Deheyn's frozen deep-sea fish collection — which included the ghastly looking hatchetfish and the wide-faced ratfish — Dr. Meyers was equally intrigued.
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For the first time ever, scientists have captured video footage of a pointy-nosed blue chimaera (aka ratfish), a species of ghost shark, hanging out in its natural environment.
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Besides these, the spotted ratfish also feeds on shrimp, worms, small fish, small crustaceans, and sea stars. Species known to prey on the spotted ratfish include soupfin sharks, dogfish sharks, Pacific halibut, pinnipeds, and pigeon guillemots.
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The cephalic clasper, or frontal tentaculum, of the spotted ratfish chimaera is shown in color. Male spotted ratfish have multiple secondary sexual characteristics, which include paired pelvic claspers, a single frontal tentaculum, and paired pelvic tentacula. The pelvic claspers are located on the ventral side of the fish. They protrude out from the pelvic fins and are responsible for the movement of sperm to the oviduct of the female.
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The ratfish prefers to maintain a safe distance from divers, and are usually not aggressive. However, if they feel their territory has been invaded, they are able to inflict a mildly toxic wound with their dorsal fin spines. As they swim, they perform barrel rolls and corkscrew turns, as if they are flying. Ratfish swim using large pectoral fins, and this has often been termed aquatic flight given the resemblance to a bird.
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A rare albino Puget Sound ratfish was discovered near Whidbey Island, Washington. It is the only pure albino among the 7.2 million specimens in the University of Washington's fish collection.
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Anisopleurodontis is a genus of prehistoric shark. There is only one species, the type species, A. pricei. It is a member of the Holocephali, the group that includes chimaeras and ratfish.
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The spotted ratfish (Hydrolagus colliei) is a chimaera found in the north- eastern Pacific Ocean. Often seen by divers at night in the Pacific Northwest, this cartilaginous fish gets its characteristic name from a pointed rat-like tail. The ratfish lays leathery egg cases on the bottom of muddy or sandy areas, which are often mistaken by divers as something inanimate. While mainly a deep-water species, it occurs at shallower depths in the northern part of its range.
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Foster, K. L. and Higham, T. E. (2010). How to build a pectoral fin: functional morphology and steady swimming kinematics of the spotted ratfish, Hydrolagus colliei. Can. J. Zool. 88, 774-780.
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The pointy-nosed blue chimaera (Hydrolagus trolli), also known as the pointy- nosed blue ratfish, Ray Troll's chimaera or abyssal ghostshark, is a species of deep-sea fish in the family Chimaeridae.
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Encyclopedia of Fishes. San Diego: Academic Press. p. 69. . Huber, D.R., Dean, M.N., Summers, A. P. 2008. . Hard prey, soft jaws and the ontogeny of feeding mechanics in the spotted ratfish Hydrolagus collie.
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Both the upper and lower teeth are plate-shaped (9). Of note, the spotted ratfish does not have a cartilaginous appendage to the frontonasal region (2), which is a common feature of the chimera.
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Akmajian, A.M.; Lambourn, D.M.; Lance, M.M.; Raverty, S.; and Gaydos, J.K. (2012). Mortality related to spotted ratfish (Hydrolagus colliei) in Pacific harbor seals (Phoca vitulina) in Washington State. J Wildl Dis. 48(4): 1057-1062.
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Spotted ratfish typically live closer to the shore in the northern part of their range than in the southern, but it is also found as shallow as off California. Spotted ratfish tend to move closer to shallow water during the spring and autumn, then to deeper water in summer and winter. For most of the year, they prefer temperatures between , but seasonally they do move into slightly warmer water. They can most commonly be found living near the sea floor in sandy, muddy, or rocky reef environments.
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Dark edges outline both the caudal and dorsal fins, whereas the pectoral fins have a transparent outline. Their pectoral fins are large and triangular, and extend straight out from the sides of their bodies like airplane wings. They have a venomous spine located at the leading edge of their dorsal fin, which is used in defense. It does not present a serious danger to humans, but can cause painful wounds and has been known to kill harbor seals that ate spotted ratfish (caused by the spine penetrating vital tissue in the stomach or esophagus after the ratfish was swallowed).
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"Egg capsule morphology provides new information about the interrelationships of chondrichthyan fishes." Journal of Systematic Palaeontology 12.3 (2013): 389-99. However, there are some key morphological differences that are specific to chimaeras. The spotted ratfish chimaera is also known as Hydrolagus colliei.
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Their bodies were probably broad and flattened, like modern rays. "Bradyodonti" can also refer to the present-day Chimaera or ratfish of the order Chimaeriformes, which have an upper jaw fused to the braincase and a flap of skin covering the gill slits.
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Unlike most of its relatives, which are entirely restricted to deep waters, the spotted ratfish has been held in public aquaria. It has also been bred in such aquaria, where two of the main issues are the requirements of low light and low temperature (generally kept at ).
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The spotted ratfish swims slowly above the seafloor in search of food. Location of food is done by smell. Their usual hunting period is at night, when they move to shallow water to feed. They are particularly drawn to crunchy foods such as crabs and clams.
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Stensioella heintzi has an elongated body, a whip-like tail, and long, wing- like pectoral fins. In life, the animal would have looked vaguely like an elongated ratfish. Like the sympatric Gemuendina, S. heintzi had armor made up of a complex mosaic of small, scale-like tubercles.
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Troll is a lifelong music aficionado and musician. He and his band, the Ratfish Wranglers, play festival, saloon, and dance party dates from Alaska to California, appearing at Salmonfest (formerly Salmonstock) in Ninilchik, Alaska, the Fisher Poets Gathering in Astoria, Oregon, and many other events around the Pacific Northwest.
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Some fish, e.g. the spotted ratfish (Hydrolagus colliei) and batiform fish (electric rays, sawfishes, guitarfishes, skates and stingrays) use their pectoral fins as the primary means of locomotion, sometimes termed labriform swimming. Marine mammals oscillate their body in an up-and-down (dorso-ventral) direction. Other animals, e.g.
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Roderick McKenzie. Oxford: Clarendon Press. and λαγώς/λαγῶς, meaning hare, and the specific name honors Alexander Collie, who was a ship surgeon and early naturalist. The spotted ratfish is common in much of its range, not typically eaten by humans (the flesh is bland with an unpleasant aftertaste), and not commercially caught.
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Like some sharks, spotted ratfish are oviparous. Their spawning season peaks during the spring to autumn. During this time, the female releases up to two fertilized eggs into sand or mud areas of the seabed every 10–14 days. The extrusion process can last 18–30 hours and the actual laying can last another 4–6 days.
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Acta Neuropathologica. 2017;133 (1):79-90. . Braak's early research focused on the morphology of the central nervous system of chondrichthyan fishes. In the holocephalan species Chimaera monstrosa (ratfish), he described, in the basal midline of the diencephalon, a previously unknown ependymall structure adjacent to the rostral part of the optic chiasma referred to as the ‘organon vasculare praeopticum’.
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The Eugeneodontida is an extinct and poorly known order of bizarre cartilaginous fishes. They possessed a unique "tooth-whorl" on the symphysis of the lower jaw and pectoral fins supported by long radials. The palatoquadrate was either fused to the skull or reduced. Now determined to be within the Holocephali, their closest living relatives are ratfish.
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The interior of the pelvic clasper is supported by cartilage and separates into two branches, ultimately ending in a fleshy lobe on the posterior end. The cephalic clasper (tentaculum) is a unique, club-like organ not found in any other vertebrates.Raikow, R. J., & Swierczewski, E. V. (1975). Functional anatomy and sexual dimorphism of the cephalic clasper in the pacific ratfish (Chimaera collei).
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Chimaera egg case NOAAS Okeanos Explorer. Visible on its snout are tiny pores which lead to electroreceptor cells. Chimaeras live in temperate ocean floors down to deep, with few occurring at depths shallower than . Exceptions include the members of the genus Callorhinchus, the rabbit fish and the spotted ratfish, which locally or periodically can be found at relatively shallow depths.
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Shortnose chimaeras have a venomous spine on their backs, which is sufficiently dangerous to injure humans. They are found in temperate and tropical marine waters worldwide. Most species are restricted to depths below , but a few, notably the spotted ratfish and rabbit fish, can locally be found at relatively shallow depths. They range from in maximum total length, depending on species.
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The spotted ratfish can be found in the northeastern Pacific Ocean, ranging from Alaska to Baja California, with an isolated population in the Gulf of California. They are abundant in much of their range. They be found most commonly off the Pacific Northwest. The range of depths in which this fish is found extends from below sea level, but it is most common between .
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Typically, fan-shaped muscles experience varying degrees of fiber strain. This is largely due to the different lengths and varying insertion points of the muscle fibers. Studies on ratfish have looked at the strain on fan-shaped muscles that have a twisted tendon. It has been found that strain becomes uniform over the face of a fan-shaped muscle with the presence of a twisted tendon.
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Three principal sources exist for comparative evolutionary investigations: Fossils, fresh-preserved post-mortem or in vivo studies. The fossil record is dominated by structures that were already biomineralized during the lifetime of the respective organism (in the case of vertebrates, mainly teeth and bones). Brains, like other soft tissues, rarely fossilize, but occasionally they do. The probably oldest vertebrate brain known today belonged to a ratfish that lived around 300 million years ago (Pradel et al.
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This makes them harder to detect by animals such as ratfish which can sense the electrical signals given off by the most minute muscle movement. The mantle of a scaphopod is entirely within the shell. The foot extends from the larger end of the shell, and is used to burrow through the substrate. The scaphopod positions itself head down in the substrate, with the apical end of the shell (at the rear of the animal's body) projecting upward.
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The mouth is small and contains one pair of forward-directed, incisor-shaped teeth in the bottom jaw and two pairs in the top jaw. Unlike sharks, which have sharp teeth that are easily replaceable, spotted ratfish teeth are plate-shaped, mineralized, and permanent, which assist them in grinding their prey. Like many bony fishes, but unlike its sister group, the Elasmobranchii, the upper jaw of the chimaera is fused with the skull.. [null ↑] Stevens, J.; Last, P.R. (1998). Paxton, J.R.; Eschmeyer, W.N., eds.
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The Galápagos ghostshark has been observed to occur on steep slopes, in areas containing stones and boulders with dispersed sand and silt. The nine specimens in the original description were found in depths of . This is a shallower range than most species in Hydrolagus, but the two most closely related species to the Galápagos ghostshark – the spotted ratfish (Hydrolagus colliei) and the dark ghostshark (Hydrolagus novaezealandiae) – do live in shallower depths. The specimens were found close to the sea floor, in groups or alone.
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Restoration of a S. altonensis pair The spine-brush complex occupies the same site as the first dorsal fin on other ratfish and contains a basal plate extending inside a usually posterior-pointing dorsal spine composed of trabecular dentine. The spines resemble those of modern sharks and rays but curiously lack any enamel-like surface tissue. The trabecular dentine contains patches of fibers suggesting attachments to the epaxial musculature. The way these muscles would have been positioned implies that the spine could have been moved in anterio-posterior direction.
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The specific name of the species was named as such in honor of McCosker. Didier said, "Determining Hydrolagus mccoskeri was a new species of ratfish wasn't difficult, but going through all the verification steps required a great deal of time." The holotype of the species is a juvenile female, found by John McCosker, R. Grant Gilmore, and Bruce Robinson on November 17, 1995, southeast of San Cristóbal Island. The paratype is also a juvenile female, discovered by John McCosker and John Ross on July 6, 1998, located close to Española Island.
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Northern elephant seals eat a variety of prey, including mesopelagic fish such as myctophids, deep-water squid, Pacific hake, pelagic crustaceans, relatively small sharks, rays, and ratfish. Octopoteuthis deletron squid are a common prey item, one study found this species in the stomachs of 58% of individuals sampled off the coast of California. A female northern elephant seal was documented in 2013 by a deep sea camera at a depth of , where it consumed a Pacific hagfish, slurping it up from the ocean floor. The event was reported by a Ukrainian boy named Kirill Dudko, who further reported the find to scientists in Canada.
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Common animals on Coronation Island include American black bears, black-tailed deer, bald eagles, and wolves. The ocean around the island ranges from to and supports a handful of coral reef areas as well as sea otters, Steller's sea lions, harbor seals, and humpback whales. Fish and shellfish that inhabit the water around the island include king salmon, red salmon, silver salmon, pink salmon, chum salmon, halibut, lingcod, Pacific cod, a variety of rockfish, greenling, ratfish, dog sharks, dungeness crab, tanner crab, king crab, shrimp, prawns, scallops, abalone, clams, and jellyfish. Great white sharks that have traveled up on warm currents have been reported off the island.
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He also served as the chairman of the Neurobiology Unit of Scripps Institution of Oceanography in La Jolla, CA. One reason for his move to UCSD was that he hoped to bridge the gap between Marine Biology and medicine. Bullock published a vast array of papers. Other than the species previously mentioned, he also studied the nervous systems of corals, sea urchins, spirunculids, Limulus, Aplysia, starfish, rattlesnakes, rays, sharks, porpoises, sea lions, cuttlefish, catfish, sloths, manatees, salamanders, frogs, turtles, hagfish, crayfish, tuna, ratfish, bats, crabs, octopodes, snakes, rats and humans. In 1965 together with Adrian Horridge, Bullock published the seminal two-volume “bible of invertebrate neurobiology”: Structure and Function in the Nervous System of Invertebrates.
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