What is an anadromous fish? A catadromous fish?

Answer 1

Diadromous is a general category describing fish that spend portions of their life cycles partially in fresh water and partially in salt water. These represent both anadromous and catadromous fish. Anadromous fishes spend most of their adult lives at sea, but return to fresh water to spawn. Catadromous is a term used for a special category of marine fishes who spend most of their adult lives in fresh water, but must return to the sea to spawn. True anadromous fish migrate from the ocean to spawn in freshwater rivers or sometimes in the brackish upper reaches of the estuary. Catadromous fishes, on the other hand, spawn in the marine environment and move to the riverine environment to mature over a several-year period.

Answer 2

What is an anadromous fish? Anadromous fish are marine fish species that migrate each year to a spawning area. Each spring they leave the open ocean and travel into estuaries, coastal rivers, and freshwater rivers and creeks to release their eggs. The eggs are fertilized outside the female’s body. If conditions are right, the fertilized eggs hatch within a few days. The tiny fish larvae will begin their lives in the upper estuary nurseries where marshlands and submerged aquatic vegetation (SAV) provide food and cover from predators. As the season moves into late summer and early fall, the juvenile fish leave the shelter of the upper estuary and begin a journey to the open ocean from which their parents came. During their life cycle, the fish encounter many perils and not all of them will survive to reproductive maturity. The survivors will complete the cycle by taking the same journey their parents took years earlier. The full-grown adults are greatly valued by animals and humans as a food source.