Freshwater eel
| Anguillidae Temporal range: Danian–0 Early Paleocene (Danian) to Present |
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| American eel, Anguilla rostrata | |
| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Actinopterygii |
| Order: | Anguilliformes |
| Family: |
Anguillidae Rafinesque, 1810 |
| Genus: |
Anguilla Garsault, 1764 |
| Species | |
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See text. |
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See text.
The Anguillidae are a family of ray-finned fish that contains the freshwater eels. The nineteen species and six subspecies in this family are all 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 fresh water 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.
Members of this family are catadromous, meaning they spend their lives in freshwater rivers, lakes, or estuaries, and return to the ocean to spawn. The young eel larvae, called , live only in the ocean and consume small particles called marine snow. They grow larger in size, and in their next growth stage, they are called glass eels. At this stage, they enter estuaries, and when they become pigmented, they are known as elvers. Elvers travel upstream in freshwater rivers, where they grow to adulthood. Some details of eel reproduction are as yet unknown, and the discovery of the spawning area of the American and European eels in the Sargasso Sea is one of the more famous anecdotes in the history of ichthyology. The spawning areas of some other anguillid eels, such as the Japanese eel, and the giant mottled eel, were also discovered recently in the western North Pacific Ocean.
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 small pectoral fins to help them navigate along river bottoms. Their scales are thin and soft. Freshwater eels go through physical changes in their bodies when going to and from the ocean for different stages of life.
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Wikipedia