Creature Feature: Bluefin Tuna

bluefin tunaNote: Regulation changes regarding filleting tuna at sea, and the bluefin tuna bag limit, are now in effect.

Bluefin tuna may be found statewide off California, with the majority of fish landed weighing between 15 and 30 lb. (1- to 2-year-old fish).  They range worldwide in all but the very coldest seas.

Distinguishing Characteristics

  • Dark blue above, gray below.
  • Body cigar-shaped and robust, head conical, mouth large.
  • Relatively short pectoral fins.
  • Bluefin tuna can be distinguished from other short-finned tunas by comparing the livers upon cleaning: bluefin tuna liver is heavily striated (covered with blood vessels).  It is the only tuna with both relatively short pectoral fins and a heavily striated liver.

Life History & Other Notes
Bluefin tuna are seasonal visitors to California waters.  While in the neighborhood, they feast mainly upon anchovies; they will also take other fishes such a Pacific whiting and sauries, and pelagic red crabs.

Bluefin tuna usually appear off California beginning in May.  Since they are a temperate tuna, their availability to anglers depends on water temperatures in the 62° to 68° F range.  They can be located by either trolling feathers or anchoring at a spot known to be frequented by bluefin tuna, and chumming with live anchovies.  Once the fish are attracted, anglers use light line (12 lb. test or lighter), small hooks (no. 4 or smaller) and the “hottest” bait available that season, usually live anchovies or pieces of squid.


 Bluefin Tuna Quick Facts:

Scientific Names: Thunnus orientalis

Other Common Names: leaping tuna, football, BFT

Range & Habitat: Statewide

Length & Weight: To 6+ ft. and 1000 lb.

Life Span: To 16 years

Diet & Suggested Bait/Lures: Feeds on fishes such as anchovy, Pacific whiting and sauries; also feeds on pelagic red crabs.  Try trolling an artificial lure or using live anchovies or pieces of squid.


Excerpt from the California Finfish and Shellfish Identification Book. Single copies of the book are available to California residents free of charge by emailing a request to publications@wildlife.ca.gov.

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