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European eel : ウィキペディア英語版 | European eel
The European eel (''Anguilla anguilla'') is a species of eel, a snake-like, catadromous fish. They can reach a length of in exceptional cases, but are normally around , and rarely reach more than . ==Life history== (詳細はlife history was a mystery for centuries, as fishermen never caught anything they could identify as a young eel. Unlike many other migrating fish, eels begin their lifecycle in the ocean and spend most of their lives in fresh water, returning to the ocean to spawn and then die. In the early 1900s, Danish researcher Johannes Schmidt identified the Sargasso Sea as the most likely spawning grounds for European eels.〔Schmidt, J. (1912) Danish researches in the Atlantic and Mediterranean on the life-history of the Fresh-water Eel (''Anguilla vulgaris'', Turt.). Internationale Revue der gesamten Hydrobiologie und Hydrographie 5: 317-342.〕 The larvae (leptocephali) drift towards Europe in a 300-day migration. When approaching the European coast, the larvae metamorphose into a transparent larval stage called "glass eel", enter estuaries, and start migrating upstream. After entering fresh water, the glass eels metamorphose into elvers, miniature versions of the adult eels. As the eel grows, it becomes known as a "yellow eel" due to the brownish-yellow color of their sides and belly. After 5–20 years in fresh water, the eels become sexually mature, their eyes grow larger, their flanks become silver, and their bellies white in color. In this stage, the eels are known as "silver eels", and they begin their migration back to the Sargasso Sea to spawn.
抄文引用元・出典: フリー百科事典『 ウィキペディア(Wikipedia)』 ■ウィキペディアで「European eel」の詳細全文を読む
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