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Anadromous
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Such migrations are usually done for better feeding or to reproduce, but in other cases the reasons are unclear. Fish migrations involve movements of schools of fish on a scale and duration larger than those arising during normal daily activities. Some particular types of migration are ''anadromous'', in which adult fish live in the sea and migrate into fresh water to spawn; and ''catadromous'', in which adult fish live in fresh water and migrate into salt water to spawn. Marine forage fish often make large migrations between their spawning, feeding and nursery grounds. Their movements are associated with ocean currents and with the availability of food in different areas at different times of the year. The migratory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lamprey
Lampreys (sometimes inaccurately called lamprey eels) are a group of Agnatha, jawless fish comprising the order (biology), order Petromyzontiformes , sole order in the Class (biology), class Petromyzontida. The adult lamprey is characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin , which may mean "stone licker" ( "to lick" + "stone"), though the etymology is uncertain. "Lamprey" is sometimes seen for the plural form. About 38 extant species of lampreys are known, with around seven known extinct species. They are classified in three families—two small families in the Southern Hemisphere (Geotriidae, Mordaciidae) and one large family in the Northern Hemisphere (Petromyzontidae). Genetic evidence suggests that lampreys are more closely related to hagfish, the only other living group of jawless fish, than they are to jawed vertebrates, forming the superclass Cyclostomi. The oldest fossils of stem-group lampreys are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animal Migration
Animal migration is the relatively long-distance movement of individual animals, usually on a seasonal basis. It is the most common form of migration in ecology. It is found in all major animal groups, including birds, mammals, fish, reptiles, amphibians, insects, and crustaceans. The cause of migration may be local climate, local availability of food, the season of the year or for mating. To be counted as a true migration, and not just a local dispersal or irruption, the movement of the animals should be an annual or seasonal occurrence, or a major habitat change as part of their life. An annual event could include Northern Hemisphere birds migrating south for the winter, or wildebeest migrating annually for seasonal grazing. A major habitat change could include young Atlantic salmon or sea lamprey leaving the river of their birth when they have reached a few inches in size. Some traditional forms of human migration fit this pattern. Migrations can be studied using tradition ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spawn (biology)
Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is known as spawning. The vast majority of aquatic and amphibious animals reproduce through spawning. These include the following groups: * Bony fishes * Crustaceans (such as crabs, shrimps, etc.) *Mollusks (such as oysters, octopus, squid) *Echinoderms (such as sea urchins, sea stars, sea cucumbers, etc.) * Amphibians (such as frogs, toads, salamanders, newts) * Aquatic insects (such as dragonflies, mayflies, mosquitoes) *Coral, which are living colonies of tiny, aquatic organisms—not plants, as they are sometimes perceived to be. Corals, while appearing sedentary or botanical by nature, actually spawn by releasing clouds of sperm and egg cells into the water column, where the two mix. As a general rule, aquatic or semiaquatic reptiles, birds, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Salmon
Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native to tributary, tributaries of the North Atlantic (''Salmo'') and North Pacific (''Oncorhynchus'') basins. ''Salmon'' is a colloquial or common name used for fish in this group, but is not a scientific name. Other closely related fish in the same family include trout, Salvelinus, char, Thymallus, grayling, Freshwater whitefish, whitefish, lenok and Hucho, taimen, all coldwater fish of the subarctic and cooler temperate regions with some sporadic endorheic populations in Central Asia. Salmon are typically fish migration, anadromous: they hatch in the shallow gravel stream bed, beds of freshwater headstreams and spend their juvenile fish, juvenile years in rivers, lakes and freshwater wetlands, migrate to the ocean as adults and live like sea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrostei
Chondrostei is a subclass of non- neopterygian ray-finned fish. While the term originally referred to the paraphyletic grouping of all non-neopterygian ray-finned fish, it was redefined by Patterson in 1982 to be a clade comprising the Acipenseriformes (which includes sturgeon and paddlefish) and their extinct relatives. Taxa commonly suggested to represent relatives of the Acipenseriformes include the Triassic marine fish '' Birgeria'' and the Saurichthyiformes, but their relationship with the Acipenseriformes has been strongly challenged on cladistic grounds. Coccolepididae, a group of small weakly ossified Jurassic and Cretaceous fish found in both marine and freshwater environments, have also been suggested to be close relatives of the Acipenseriformes. However, this has never been subject to cladistic analysis. Near & Thacker (2024) also recovered the ptycholepiform '' Boreosomus'' as a stem-acipenseriform. The following taxa are known: * Subclass Chondrostei ** Genus � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petromyzontidae
Petromyzontidae are a family of lampreys native to the Northern Hemisphere, comprising the vast majority of living lampreys. Petromyzontids have the highest number of chromosomes (164–174) among vertebrates. Genera * '' Caspiomyzon'' * '' Entosphenus'' * '' Eudontomyzon'' * '' Ichthyomyzon'' * ''Lampetra ''Lampetra'' is a genus of lampreys in the family Petromyzontidae. Phylogenetic studies indicate that this genus as presently defined is polyphyletic, with species of this genus from western North America forming a clade that forms the sister ...'' * '' Lethenteron'' * '' Petromyzon'' * '' Tetrapleurodon'' References External links FishBase.org: Details for family Petromyzontidae – the Northern lampreys Fish described in 1827 Fish families Fish of Asia Fish of Europe Fish of North America Fish of the Atlantic Ocean Fish of the Pacific Ocean Taxa named by Antoine Risso {{jawless-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mordaciidae
''Mordacia'' is a genus of lamprey, the sole genus of the family Mordaciidae, also known as the southern topeyed lampreys. The family Mordaciidae is most closely related to the lamprey family Geotriidae, which has a similar Gondwanan distribution, and both families diverged during the Early Cretaceous. Together, their common ancestor diverged from the Petromyzontidae during the Middle Jurassic. They are found in Chile and Australia; the Chilean and one Australian species (''M. lapicida'' and ''M. mordax'') are anadromous fish that spawn in Pacific-draining river basins and mature in the ocean, while the other Australian species (''M. praecox'') spends its whole life in freshwater. Phylogenetic evidence indicates ancient divergences within this genus, with the Chilean and Australian lineages diverging from one another during the Late Cretaceous (100 mya), although both Australian species only diverged from each other during the Pleistocene. Species There are currently three rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geotriidae
''Geotria'' is the only genus in the lamprey family Geotriidae. It has 2 known species: '' Geotria australis'' (pouched lamprey) and '' Geotria macrostoma'' (Argentinian lamprey). Both species were considered conspecific until ''G. macrostoma'' was revived in a 2020 study. The family Geotriidae is most closely related to the lamprey family Mordaciidae, which has a similar Gondwanan distribution, and both families diverged during the Early Cretaceous. Together, their common ancestor diverged from the Petromyzontidae during the Middle Jurassic. ''G. australis'' spawns in Pacific-draining river basins in on either side of the southern Pacific (both Australasia and Chile), while ''G. macrostoma'' spawns in Atlantic-draining basins in southern South America and nearby subantarctic islands. Despite the occurrence of both species in South America and both formerly being considered conspecific, phylogenetic studies suggest that the lineages of both species diverged during the Late Creta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclostomi
Cyclostomi, often referred to as Cyclostomata , from Ancient Greek κύκλος (kúklos), meaning "circle", and στόμα (stóma), meaning "mouth", is a superclass of vertebrates that comprises the living jawless fish classes: the lampreys and hagfishes. Both groups have jawless mouths with horny epidermal structures that function as teeth called ceratodontes, and branchial arches that are internally positioned instead of external as in the related jawed fishes. The superclass was named by Joan Crockford-Beattie. Possible external relationships This taxon is often included in the paraphyletic infraphylum Agnatha, which also includes several groups of extinct armored fishes called ostracoderms. Most fossil agnathans, such as galeaspids, thelodonts, and osteostracans, are more closely related to vertebrates with jaws (called gnathostomes) than to cyclostomes. Biologists historically disagreed on whether cyclostomes are a clade. The "vertebrate hypothesis" h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
