Reproduction, development and morphological variation of laboratory-cultured C. racemosa var.peltata. Retrieved 2011-08-22 Mass spawnings sometimes take place in the Caribbean Sea and normally do so just before dawn. There were 39 such mass spawnings during a period of 125 days and the days on which they took place showed no relation to the tidal or lunar cycles."Mass Spawning by Green Algae on Coral Reefs" Retrieved 2011-08-22.
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Similar mass spawnings take place in the Mediterranean Sea causing a cloud of green gametes to be released in the water approximately 14 minutes before sunrise.Sexual reproduction of the invasive green alga Caulerpa racemosa var. occidentalis in the Mediterranean Sea. Retrieved 2011-08-22.
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Its ability to protrude its jaw 3.5% standard length limits its diet to about 1% evasive prey. Amatitlania septemfasciata is an egg layer and a cave spawner. In breeds in crevices in the rocks at the bottom of the river. Spawnings typically result in 200 to 250 fry.
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However, as they are territorial each individual will need its own cave; damaged tails due to territorial disputes is a sign there are not enough retreats. They are highly adaptable and can live in almost any water condition (though extremes should be avoided). There have been no known spawnings in captivity.
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Spawning takes place from spring through fall. In the southernmost populations, up to eight spawnings are possible in a season. Spawning takes place most often at high tide and when the moon is new or full. Maximal spawning occurs when high spring tides coincide with night, though spawning during the day remains possible.
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Males may participate in several spawnings per run. The eggs incubate a few inches deep in the sand above the level of subsequent waves. They are not immersed in seawater, but are kept moist by the residual water in the sand. While incubating, they are subject to predation by shore birds and sand-dwelling invertebrates.
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These data strongly indicate the 60-cm (20-in) size limit for Murray cod is inadequate and should be increased substantially to allow for a greater chance of reproduction before capture. Large female Murray cod in the 15– to 35-kg (35– to 80-lb) range are the most important breeders because they produce the most eggs and for other reasons; large females in most fish species are also important because they produce larger larvae with larger yolk sacs, and are also more experienced breeders that display optimal breeding behaviours. Such large females may also have valuable, successful genes to pass on. All of these factors mean the spawnings of large female fish have far higher larval survival rates and make far greater reproductive contributions than the spawnings of small female fish.
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1186–1189 Babcock, R.C., Bull, G.D., Harrison, P.L., Heyward A.J., Oliver, J.K., Wallace, C.C., Willis, B.L. 1986. Synchronous spawnings of 105 scleractinian coral species on the Great Barrier Reef. Marine Biology 90, issue 3, pp. 379–394. Since they first observed reproductive synchrony in coral in Australia it has been observed in other countries, but at different times of the year.
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"Breeding Coral Red Pencilfish and other Pencilfishes" by Dr. Stanley H. Weitzman and Marilyn Weitzman, "Tropical Fish Hobbyist", February, 2002 Males will establish and defend small territories. Unlike its congener, N. eques, which prefers the upper strata of the aquarium, N. unifasciatus tends to congregate in the mid to lower reaches. This is the only species of Nannostomus in the aquarium trade for which there is no recorded account of a successful spawning in captivity to date, this despite it being a widely kept and much admired aquarium species since the 1920s. Two reports of purported successful spawnings in the 1950s, published in aquarium literature—one in the Belgian magazine, "Notre Aquarium," and the other in the American magazine, "The Aquarium"—involved misidentification of the species, the spawnings having occurred for N. eques and N. harrisoni respectively, not N. unifasciatus.
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This shark has been observed deviating from its nocturnal habits to feed on chokka squid (Loligo reynaudii) during their mass spawnings. The broadnose sevengill shark (Notorynchus cepedianus) is known to prey on this species. During the summer, the sharptooth houndshark forms groups in shallow water. These aggregations are particularly well-documented in False Bay and may be related to reproduction, given the presence of many pregnant females.
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The spawning occurs at night for several consecutive days and is the most common way in which scleractinian corals externally fertilize. The reason for this phenomenon is still widely unknown, but its importance is evident; whole populations of coral species engage in this action annually.Babcock, R. C., et al. “Synchronous Spawnings of 105 Scleractinian Coral Species on the Great Barrier Reef.” Marine Biology, vol.
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The female constructs a depression in a location in the stream bed, sometimes referred to as a "redd", where groundwater percolates upward through the gravel. One or more males approach the female, fertilizing the eggs as the female expresses them. A majority of spawnings involve peripheral males which directly influences the number of eggs that survive into adulthood. In general, the larger the number of peripheral males present, the more likely the eggs will be cannibalized.
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Crabs compete with other individuals before, during, and after insemination, so mate guarding is very important for reproductive success. After mating, a male must continue to guard the female until her shell has hardened. Inseminated females retain spermatophores for up to one year, which they use for multiple spawnings in high salinity water. During spawning, a female extrudes fertilized eggs onto her swimmerets and carries them in a large egg mass, or sponge, while they develop.
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There is some evidence that axolotls might seek out appropriately-sized gravel for use as gastrolithsWings, O A review of gastrolith function with implications for fossil vertebrates and a revised classification Acta Palaeontologica Polonica 52 (1): 1–16 based on experiments conducted at the University of Manitoba axolotl colony.Gordon, N, Gastroliths – How I Learned to Stop Worrying and Love Gravel.Björklund, N.K. (1993). Small is beautiful: economical axolotl colony maintenance with natural spawnings as if axolotls mattered.
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Eventually commercial growers began to cultivate the Pacific oyster, and by the mid-1970s, it had become the main farm-raised oyster. Pacific oysters have well-established international markets, grow three times faster than native rock oysters, reach a larger size, have several spawnings each year and produce more consistent quantities of spat.NIWA: Aquaculture species: Pacific Oysters National Centre for Fisheries & Aquaculture. Retrieved 28 February 2009 In 1977 Pacific oysters appeared in the Marlborough Sounds, and farming began there in the 1990s.
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The time between spawnings is unknown at present. Eggs are not strewn freely into the water, but they are not deposited in clutches to a prepared surface either; rather, it seems, that they are hidden away in vegetation as a loose batch. Courting males will seek out and try to defend a patch of dense vegetation. While pursuit swimming has been observed, it does not seem to be connected directly to the actual act of reproduction in which the male displays to a passing female, and tests her readiness with a brief chase.
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They are hermaphroditic and have distinct tongue-shaped gonads which are red or orange in colour for the female gonad and white for the male. It is estimated that a three-year old scallop releases 15 - 21 million oocytes per emission. There appear to be two spawnings in many parts of the range, normally there is a partial one in the Spring and a full one in late August, however younger scallops have a single spawning event in the late summer. In some areas this pattern is reversed and the major spawning is in the Spring.
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Three localities that were sampled by Vogler et al. are of particular interest: Palau Sebibu, UEA and Oman were found to have two clades/sibling species in sympatry. These are important to investigate the nature of the co-existence and barriers to introgression of genetic material. A. planci as a taxon is a generalist, being amongst the most ubiquitous of large coral predators on coral reefs, feeding on virtually all hard coral species, reproducing during summer without a pattern of spawning and often participating in mass multi-species spawnings, and releasing vast amounts of gametes that trigger spawning in other individuals.
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Like its close relative the pyjama shark, it will temporarily abandon its nocturnal habits to take advantage of the daytime mass spawnings of the chokka squid (Loligo vulgaris reynaudi), which occur unpredictably year-round with a peak from October to December. The sharks lie motionless amongst the squids' egg masses with their heads hidden, and make sudden lunges at female squid that have descended to the sea floor to attach their eggs. The leopard catshark produces light-colored egg capsules that it attaches to underwater structures. The leopard catshark is oviparous and apparently reproduces throughout the year.
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In some species of anglerfish, when a male finds a female, he bites into her skin, and releases an enzyme that digests the skin of his mouth and her body, fusing the pair down to the blood-vessel level. The male becomes dependent on the female host for survival by receiving nutrients via their shared circulatory system, and provides sperm to the female in return. After fusing, males increase in volume and become much larger relative to free-living males of the species. They live and remain reproductively functional as long as the female lives, and can take part in multiple spawnings.
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All species are oceanic spawners. Reports of A. trutta being anadromous and spawning in freshwater are not correct; this may be due to confusion with sea-run specimens of exotic brown trout, (Salmo trutta), or anadromous populations of native spotted galaxias, (Galaxias truttaceus). A. georgianus is thought – due to females retaining both ripe and unripe eggs – to be "partial spawners"; that is, they may spawn over a long period with no real peaks. In contrast, A. trutta and A. truttaceus are thought to be "serial batch spawners", completing their spawning season after a series of small "burst" spawnings.
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When a male finds a female, he bites into her skin, and releases an enzyme that digests the skin of his mouth and her body, fusing the pair down to the blood-vessel level. The male becomes dependent on the female host for survival by receiving nutrients via their shared circulatory system, and provides sperm to the female in return. After fusing, males increase in volume and become much larger relative to free-living males of the species. They live and remain reproductively functional as long as the female lives, and can take part in multiple spawnings.
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Although it has a predilection for cephalopods, the dietary composition of this opportunistic predator generally reflects the locally available prey types. For example, in False Bay the Cape rock lobster (Jasus lalandii) is the most important food source, followed by cephalopods and then fish. Pyjama sharks have been observed seizing and tearing off tentacles from octopus and cuttlefish with a twisting motion; on one occasion three sharks were seen attacking an octopus simultaneously in this manner. During mass spawnings of the chokka squid (Loligo vulgaris reynaudi), which occur unpredictably year-round but peak from October to December, pyjama sharks deviate from their nocturnal habits and gather in substantial numbers inside the squids' "egg beds" during daytime.
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Spawning is generally driven by environmental factors such as changes in the water temperature, and their release is triggered by lighting conditions such as sunrise, sunset or the phase of the moon. Many species of Cnidaria may spawn simultaneously in the same location, so that there are too many ova and sperm for predators to eat more than a tiny percentage — one famous example is the Great Barrier Reef, where at least 110 corals and a few non-cnidarian invertebrates produce enough gametes to turn the water cloudy. These mass spawnings may produce hybrids, some of which can settle and form polyps, but it is not known how long these can survive. In some species the ova release chemicals that attract sperm of the same species.
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Estuaries are dynamic habitats with daily fluxes in salinity due to tides, and are also affected by droughts, floods and freshes (minor, temporary rises in flow), making measurements of preferred spawning salinities for wild Australian bass difficult. However, based on capture of recently spawned larval and juvenile Australian bass in estuaries, the species appears to spawn in a salinity range of 8–12 parts per thousand (salt water is approximately 36 ppt). Australian bass sperm have no viability at or below 6 ppt, but are most viable at 12 ppt, the latter probably being the most relevant fact. However, it has been reported that Australian bass spawned in salinities of 12–18 ppt, with this statement based on fishermens' reports of observing wild Australian bass spawnings and some unpublished data gathered by the NSW Fisheries Department.McDowall RM (ed.) (1996).
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Due to centuries of separation from their Lustrian brothers, the spawnings of saurus have become slightly rare and so skinks dominate in both civil life and warfare. Although similar in climate and culture to Lustria, the Southlands remain much less explored by human or High Elves and thus the Slann of the Southlands are said to have a much more complete set of Old One prophecies as they have not been pillaged by treasure hunters. However, the Slann practice of embalming their dead under pyramids is said to have had a major influence on the early Khemrian civilisation in the Land of the Dead, which suggests they were not always so isolated. They are reported to have come in conflict with the fabled "Lost Hold" of the Dwarfs, Karak Zorn, which is said to be located somewhere in the mountains of the Southlands.
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