Migratory fishes

Almost all fish species take more or less long distant migrations within their life cycle!

The reason might be the changing requirements they have in different stages of development.

For freshly hatched fry for instance waters rich in oxygen with plankton of a size that fits its nutritional needs will be the right environment. For the adult fish habitats further downstream offer a much better source of nutrition and the threat of being eaten by other fish also decreases with growing individual body size.

So for most of the fish species there is good reason to take more or less long migrations in the course of their life. Therefor almost all fish species can be regarded as Migratory Fishes.

These migrations are essential for the conservation of species.

Long Distance Migratory Fishes can move from fresh to salt water or vice versa.

Salmon and sea trout, various species of sturgeon, alice shad, lampreys and many more are species that stay in fresh water for reproduction (anadrome migratory species).

The European eel on the other hand reproduces in the sea (Sargasso Sea in the Bermuda Triangle) and spends its growth period in fresh water (katadrome migratory species).