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Leptocephalus
Leptocephalus (meaning "slim head") is the flat and transparent larva of the eel, marine eels, and other members of the superorder Elopomorpha. This is one of the most diverse groups of teleosts, containing 801 species in 4 orders, 24 families, and 156 genera. This group is thought to have arisen in the Cretaceous period over 140 million years ago.Inuoe, Jun, M. Miya, et al. “Mitogenomic evidence for the monophyly of elopomorph fishes (Teleostei) and the evolutionary origin of the leptocephalus larva.” Molecular Phylogenetics and Evolution 32 (2004): 274-286. Web. 2 Nov. 2012. Fishes with a leptocephalus larval stage include the most familiar eels such as the conger, moray eel, and garden eel as well as members of the family Anguillidae, plus more than 10 other families of lesser-known types of marine eels. These are all true eels of the order Anguilliformes. Leptocephali of eight species of eels from the South Atlantic Ocean were described by Meyer-Rochow The fish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glass Eel
The eel is a long, thin bony fish of the order Anguilliformes. The species has a catadromous life cycle, that is: at different stages of development migrating between inland waterways and the deep ocean. Because fishermen never caught anything they recognized as young eels, the life cycle of the eel was a mystery for a very long period of scientific history. Past studies of eels The European eel (''Anguilla anguilla'') was historically the one most familiar to Western scientists, beginning with Aristotle, who wrote the earliest known inquiry into the natural history of eels. He speculated that they were born of "earth worms", which he believed were formed of mud, growing from the "guts of wet soil" rather than through sexual reproduction. Many centuries passed before scientists were able to demonstrate that such spontaneous generation does not occur in nature. In 1777, the Italian Carlo Mondini located an eel's ovaries and demonstrated that eels are a kind of fish. In 1876, as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tarpon
Tarpons are fish of the genus ''Megalops''. They are the only members of the family Megalopidae. Of the two species, one (''M. atlanticus'') is native to the Atlantic, and the other (''M. cyprinoides'') to the Indo-Pacific Oceans. Species and habitats The two species of tarpons are ''M. atlanticus'' (Atlantic tarpon) and ''M. cyprinoides'' (Indo-Pacific tarpon). ''M. atlanticus'' is found on the western Atlantic coast from Virginia to Brazil, throughout the Caribbean and the coast of the Gulf of Mexico. Tarpons are also found along the eastern Atlantic coast from Senegal to South Angola." Megalops atlanticus", www.fishbase.org, 11 February 2010. ''M. cyprinoides'' is found along the eastern African coast, throughout Southeast Asia, Japan, Tahiti, and Australia. Both species are found in both marine and freshwater habitats, usually ascending rivers to access freshwater marshes." Megalops cyprinoides", www.fishbase.org, 11 February 2010. They are able to survive in brackis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Larva
A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The larva's appearance is generally very different from the adult form (''e.g.'' caterpillars and butterflies) including different unique structures and organs that do not occur in the adult form. Their diet may also be considerably different. Larvae are frequently adapted to different environments than adults. For example, some larvae such as tadpoles live almost exclusively in aquatic environments, but can live outside water as adult frogs. By living in a distinct environment, larvae may be given shelter from predators and reduce competition for resources with the adult population. Animals in the larval stage will consume food to fuel their transition into the adult form. In some organisms like polychaetes and barnacles, adults are im ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphose
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (" holometaboly"), incomplete metamorphosis ("hemimetaboly"), or no metamorphosis (" ametaboly"). Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. Generally organisms with a larva stage undergo metamorphosis, and during metamorphosis the organism loses larval characteristics. References to "metamorphosis" in mammals are imprecise and only colloquial, but historically idealist ideas of transformation an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notacanthidae
Notacanthidae, the deep-sea spiny eels, are a family of fishes found worldwide below , and as deep as . The earliest known spiny eel is '' Pronotacanthus sahelalmae'', from the Santonian of what is now Lebanon. Their bodies are greatly elongated, though more tapered than in true eels. The caudal fin is small or nonexistent, while the anal fin is lengthy, as long as half of the total body length. They feed on animals attached to or living on the sea floor, such as sea anemones, echinoderms, molluscs, and worms. Although not true eels, these fish do have a similar leptocephalus larva A larva (; plural larvae ) is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle. The ...l form. However, while the larvae of true eels are about 5–10% of the length of the adult, those of deep-sea spiny eels can grow considerably larger ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pelican Eel
The pelican eel (''Eurypharynx pelecanoides'') is a deep-sea eel. It is the only known member of the genus ''Eurypharynx'' and the family Eurypharyngidae. It belongs to the " saccopharyngiforms", members of which were historically placed in their own order, but are now considered true eels in the order Anguilliformes. The pelican eel has been described by many synonyms, yet nobody has been able to demonstrate that more than one species of pelican eel exists. It is also referred to as the gulper eel (which can also refer to members of the related genus '' Saccopharynx''), pelican gulper, and umbrella-mouth gulper. The specific epithet ''pelecanoides'' refers to the pelican, as the fish's large mouth is reminiscent to that of the pelican. Description The morphology of pelican eel specimens can be hard to describe because they are so fragile that they become damaged when they are recovered from the deep sea's immense pressure. However, certain observations about the physical chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiny Eel
The name spiny eel is used to describe members of two different families of fish: the freshwater Mastacembelidae of Asia and Africa, and the marine (and generally deep sea) Notacanthidae. Both are so-named because of their eel-like shape and sturdy fin spines. These two families are not related: the Notacanthiformes belong to the Superorder Elopomorpha, whose members are characterized by having leptocephalus larvae. The freshwater Mastacembelids do not share this characteristic and are popular specimens in the aquarium trade Fishkeeping is a popular hobby, practiced by aquarists, concerned with keeping fish in a home aquarium or garden pond. There is also a piscicultural fishkeeping industry, serving as a branch of agriculture. Origins of fishkeeping Fish have .... Mastacembelid Spiny eels originate from three places. The Middle East, Southeast Asia and Subsaharan Africa. In Africa alone there are 43 species known from two genera: ''Aethiomastacembelus'', with 19 known ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elopomorpha
The superorder Elopomorpha contains a variety of types of fishes that range from typical silvery-colored species, such as the tarpons and ladyfishes of the Elopiformes and the bonefishes of the Albuliformes, to the long and slender, smooth-bodied eels of the Anguilliformes. The one characteristic uniting this group of fishes is they all have leptocephalus larvae, which are unique to the Elopomorpha. No other fishes have this type of larvae. Taxonomy The Elopomorpha are a group of teleost fishes and are separated into several orders. * Genus †'' Bullichthys'' Mayrincka, Britob & Otero 2010 * Genus †'' Eichstaettia'' Arratia 1987 * Genus †'' Eoenchelys'' Lu 1994 * Genus †'' Elopomorphorum'' Weiler ex Martin & Weiler 1954 tolith* Order Elopiformes Gosline 1960 ** Family † Anaethaliidae Gaudant 1968 ** Suborder Elopoidei *** Family Protelopidae de Saint Seine 1949 *** Family Elopidae Bonaparte 1832/Valenciennes 1847 (tenpounders, ladyfishes) *** Family Megalopid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sargasso Sea
The Sargasso Sea () is a region of the Atlantic Ocean bounded by four currents forming an ocean gyre. Unlike all other regions called seas, it has no land boundaries. It is distinguished from other parts of the Atlantic Ocean by its characteristic brown '' Sargassum'' seaweed and often calm blue water. The sea is bounded on the west by the Gulf Stream, on the north by the North Atlantic Current, on the east by the Canary Current, and on the south by the North Atlantic Equatorial Current, the four together forming a clockwise-circulating system of ocean currents termed the North Atlantic Gyre. It lies between 20° and 35° north and 40° and 70° west and is approximately wide by long. Bermuda is near the western fringes of the sea. While all of the above currents deposit marine plants and refuse into the sea, ocean water in the Sargasso Sea is distinctive for its deep blue color and exceptional clarity, with underwater visibility of up to 61 m (200 ft). It ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anguilliformes
Eels are ray-finned fish belonging to the order Anguilliformes (), which consists of eight suborders, 19 families, 111 genera, and about 800 species. Eels undergo considerable development from the early larval stage to the eventual adult stage and are usually predators. The term "eel" is also used for some other eel-shaped fish, such as electric eels (genus ''Electrophorus''), spiny eels (family Mastacembelidae), swamp eels (family Synbranchidae), and deep-sea spiny eels (family Notacanthidae). However, these other clades evolved their eel-like shapes independently from the true eels. Eels live both in salt and fresh water, and some species are catadromous. Description Eels are elongated fish, ranging in length from in the one-jawed eel ('' Monognathus ahlstromi'') to in the slender giant moray. Adults range in weight from to well over . They possess no pelvic fins, and many species also lack pectoral fins. The dorsal and anal fins are fused with the caudal fi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anguillidae
The Anguillidae are a family of ray-finned fish that contains the freshwater eels. Eighteen of the 19 extant species and six subspecies in this family are in the genus ''Anguilla''. They are elongated fish with snake-like bodies, their long dorsal, caudal and anal fins forming a continuous fringe. They are catadromous fish, spending their adult lives in freshwater, but migrating to the ocean to spawn. Eels are an important food fish and some species are now farm-raised, but not bred in captivity. Many populations in the wild are now threatened, and Seafood Watch recommend consumers avoid eating anguillid eels. Physical description Adult freshwater eels are elongated with tubelike, snake-shaped bodies. They have large, pointed heads and their dorsal fins are usually continuous with their caudal and anal fins, to form a fringe lining the posterior end of their bodies. They have relatively well developed eyes and pectoral fins compared to saltwater eels that they use to navigate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conger
''Conger'' ( ) is a genus of marine congrid eels. It includes some of the largest types of eels, ranging up to 2 m (6 ft) or more in length, in the case of the European conger. Large congers have often been observed by divers during the day in parts of the Mediterranean Sea, and both European and American congers are sometimes caught by fishermen along the European and North American Atlantic coasts. The life histories of most conger eels are poorly known. Based on collections of their small leptocephalus larvae, the American conger eel has been found to spawn in the southwestern Sargasso Sea, close to the spawning areas of the Atlantic freshwater eels. "Conger" or "conger eel" is sometimes included in the common names of species of the family Congridae, including members of this genus. Description Congers have wide mouths with sturdy teeth, usually a variant of gray or black in coloration. They have no scales. Their body weight can reach over 57 kilograms (125 l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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