The second dorsal fin and the anal fin are both bright yellow, thus the common name, and can be very long in mature specimens, as are the pectoral fins. The main body is very dark metallic blue, changing to silver on the belly, which has about 20 vertical lines.
Yellowfins tend to school with fishes of the same size, including other species of tuna, and larger fish are often seen with dolphins, porpoises, whales and whale sharks. Yellowfins eat other fish, crustaceans, and squid.
Yellowfin buyers often recognize two grades, "Sashimi grade" and "other", although there are variations in the quality of "other" grades.
In terms of whether the yellowfin tuna fishing industry is sustainable, the jury is out. The Audobon's Seafood Guide (a guide for what types of marine food products are not eco-friendly) lists yellowfin tuna that have been troll-caught as "OK" but those that have been long-line caught as "Be Careful" (
Influence of oceanographic variability on recruitment of yellowfin tuna (Thunnus albacares) in the western and central Pacific Ocean.(Report)
Sep 01, 2009; Introduction Yellowfin tuna (Thunnus albacares) is a dominant pelagic species in equatorial waters of the world's oceans. The...