Definition of catadromous in English:

catadromous

adjective

Zoology
  • (of a fish such as the eel) migrating down rivers to the sea to spawn.

    The opposite of anadromous
    • ‘Finally, there was a September eel fishery in the rivers that sustained large runs of these catadromous fish, followed by fall hunting for elk and beavers, and by December, ice-fishing for tomcod.’
    • ‘Anguillid eels are catadromous, meaning that maturing individuals spend most of their lives in estuaries or freshwater but migrate to the ocean to reproduce.’
    • ‘Anguilla rostrata is a catadromous species that spawns in the Atlantic Ocean and ascends streams and rivers in North and South America.’
    • ‘This migration towards saltwater, in order to spawn, occurs in all catadromous species.’
    • ‘Anadromous and catadromous species such as salmon, herring and eels are more vulnerable than cod, however, because large numbers can be taken with a few strategically placed weirs.’

Origin

Late 19th century: from cata- down + Greek dromos running on the pattern of anadromous.

Pronunciation:

catadromous

/kəˈtadrəməs/