An oceanodromous fish, like an anadromous or catadromous fish, is a migratory fish. Unlike anadromous or catadromous fish, an oceanodromous fish spends its whole life in salt water. Many oceanodromous fishes are termed highly migratory species (HMS) because of their ocean basin-sized migration routes. Many HMS are high trophic level fish and they migrate in search of food in addition to spawning. Endangered Atlantic Bluefin Tuna (Thunnus thynnus) are one example of a HMS, high trophic level, oceanodromous fish. They spawn in the Gulf of Mexico and the Mediterranean Sea. Tagging studies show that the feed all around the Atlantic basin. Highly prized on the sashimi markets, bluefin spawning aggregations and schooling behavior make them particularly vulnerable to modern fishing techniques.

Atlantic Bluefina Tuna are an example of an oceanodromous fish which is highly migratory but only lives in salt water.
For more information, check out the “CAN YOU SAY ANADROMOUS, CATADROMOUS, AMPHIDROMOUS, OCEANODROMOUS, OR POTAMODROMOUS?” post on The Fisheries Blog!