The yellowtail jack is the most common California member of a family of fish known collectively as the jacks. The jacks are widely distributed throughout the tropical and semitropical oceans of the world. Some of the more well-known members of this family are the highly esteemed Florida pompano, and the aquacultured amber-jacks of Hawaii, which are often sold live for use in the better sushi bars.
The yellowtail, well-known for its fighting spirit and great speed, is one of the most popular game fish in Southern California. The yellowtail jack is vertically compressed, with a slightly rounded body. Olive with a bright-yellow vertical line, it may grow to 100 pounds, although 30 pounds is closer to average. Squid, mackerel, anchovies and red crabs make up the bulk of its diet.
Commercially, the most productive grounds are near the Coronado Islands off Mexico where most of the fish is taken by purse seine. The Southern California catch is made up of smaller fish than that of Mexico, but because it is caught by hook-and-line, it is of much better quality and commands a higher price. Since the fish often is consumed raw in sushi bars, capture and freshness are of great importance. Hamaichi is the Japanese name used to identify yellowtail jack.