Sarda lineolata

The Pacific Bonito is colored blue to violet above, with metallic luster becoming silvery ventrally. It has ten or eleven stripes on its back running obliquely from the dorsum forward, and fifteen or more rakers below the angle on the first gill. The first dorsal fin is contiguous with the second and longer than the head. The caudal peduncle is slender, and the body entirely scaled. It has no teeth on the vomer. It has a small keel on either side of the median keel on the sides of the caudal peduncle, and six to eight finlets on the dorsal and ventral surfaces of the caudal peduncle. The maximum size is a length of 48 in (120 cm) and weight of 25 lb (11 kg). When off the California coast, it is easy to identify these fish because they are the only tuna-like fish in this area that have dark slanted stripes on their dorsal side.

The Pacific bonito has two separate populations with different ranges. The Northern population is typically found between Southern California and Central Baja California. However, they can be found as far North as Southern Alaska in warmer years. The Southern population can be found off the coast of Northern Peru to Chile. The species can be found up to several hundred miles off the coast, but is most abundant in areas 15 miles (24 km) or less off the coast. Pacific bonito usually travel in schools in the open ocean and live up to depths of 110 m (360 ft). This species are considered highly migratory, and migrates up the coast with the seasons. They can migrate up to 600 miles (970 km) and move south in the winter where temperatures are warmer and north for the summer. Mature Pacific bonito are most commonly found in open ocean environments. Younger individuals are more often found in shallower areas such as kelp forests where they have places to hide, additionally being found inside harbors and bays.

Fish and squid are the main diet of the Pacific bonito, primarily the Northern anchovy and market squid. They have also been known to eat rockfish, hake, sardines, saury and mackerel. From January to June, during their spawning season, they have been found to eat equal amounts of mackerel and squid.