1. (of a fish) migrating from the ocean to freshwater rivers or streams to spawn
Usage: biology; ichthyology

Examples

• The American eel is a catadromous species that lives in freshwater but returns to the ocean to reproduce.
• Catadromous fish spend most of their lives in rivers before traveling downstream to salt water for spawning.
• Unlike anadromous salmon, catadromous eels migrate in the opposite direction to breed.
• Scientists study catadromous migration patterns to understand how dams affect fish populations.
• The catadromous lifecycle requires access to both freshwater and marine environments.