WANI Dictionary

Migration (fish migration)

Migration (fish migration) is a type of locomotory activity, which involves longer duration than that observed in the normal daily activities of the fish species.

Anadromous fish (e.g., salmon and sea lamprey) migrate from the sea into fresh water for reproduction, whereas catadromous fish (e.g., eel) migrate from fresh water into the sea for reproduction.

Definitions in the literature

• ... the word migration (as applied to animals) can evoke four different but overlapping concepts: (1) a type of locomotory activity that is notably persistent, undistracted, and straightened out; (2) a relocation of the animal that is on a much greater scale, and involves movement of much longer duration, than those arising in its normal daily activities; (3) a seasonal to-and-fro movement of populations between regions where conditions are alternately favorable or unfavorable (including one region in which breeding occurs); and (4) movements leading to redistribution within a spatially extended population [1].