Behavior
C
~15 species
Catadromous
/ /kəˈtædrəməs/ /
Etymology:
From Greek katadromos — "running downward"
Quick Definition
Describes fish that live in freshwater but migrate to the sea to spawn, as in eels.
📖 Full Definition
Catadromous fish spend most of their lives in freshwater but migrate to marine waters to reproduce. The best-known example is the European eel (Anguilla anguilla), which lives in rivers for 8–20 years then undertakes a 5000 km migration to spawn in the Sargasso Sea. Unlike anadromous fish, catadromous species spawn only once (semelparity), then die. The inverse of anadromy, catadromy is far less common (~15 species vs. ~250 anadromous species).
💡 Examples & Context
European eel, American eel (Anguilla rostrata), and some mullet species are catadromous.
⭐ Best Known Example
Classic example
European Eel
✏️ Also Written As
Alternative spellings / forms
catadromy