Anguillidae

American eel

Anguilla rostrata

Leaving rivers in autumn for the Sargasso Sea

• Brown
• Gray
• Cross-climate
• Temperate
• Tropical
• Estuary
• Globally widespread
• Freshwater fish
• Anguilliform
• Large
• Tropical fish

Traversing vast freshwater river drainages and epic western Atlantic oceanic currents, the American eel is a highly resilient catadromous teleost native to the eastern river basins of North America. Its elongated, snake-like body is protected by thick mucous layers and small, deeply embedded scales, with continuous dorsal, caudal, and anal fins creating an unbroken swimming ribbon. In its continental river growth phase (yellow eel), it displays an olive-brown to slate-grey back with a pale yellowish belly, before transforming prior to ocean migration into a silver eel marked by metallic bronze dorsal skin, silver flanks, and enlarged eyes. Anatomically distinguished from the closely related European eel by having fewer vertebrae (103 to 111), it ranges from Greenland and the Gulf of St. Lawrence along the Atlantic seaboard and Gulf of Mexico to the Caribbean and northern South America. Adults migrate thousands of miles into the deep, warm Sargasso Sea to spawn once and perish, while transparent glass eels migrate into coastal estuaries. Nocturnal bottom feeders capture crustaceans, worms, and fishes. Maximum total length reaches one hundred and fifty-two centimetres.

Sources: US Fish & Wildlife Service — American Eel, Anguilla rostrata