The Pacific bonito is an important gamefish, valued more for sport than for food, as is the Atlantic bonito.
Identification
Similar in size and pigmentation to the Atlantic bonito, the Pacific bonito is distinguished from most other bonito by the lack of teeth on its tongue and the possession of a straight intestine without a fold in the middle.
The Pacific bonito has 17 to 19 spines on its first dorsal fin and is the only tunalike fish on the
California coast that has slanted dark stripes on its back. Like other bonito, its body is cigar shaped and somewhat compressed, with a pointed and conical head and a large mouth. It is dark
blue above, and its dusky sides become silvery below.
Size/Age
Pacific bonito can grow to 25 pounds and 40 inches, although they are usually much smaller. The all-tackle world record is 14 pounds, 2 ounces. Fast-growing fish, bonito will be 6 to 10 inches long by the early part of their first
summer, weighing 3 pounds by that fall and 6 to 7 pounds the following spring.
Life history/Behavior
Pacific bonito form schools by size; at 2 years old, they reach sexual maturity. Spawning occurs sometime between September and February. Although spawning is usually successful each year in the southern part of their range, it may not be successful each year farther north. The free-floating eggs require about 3 days to hatch at average spring water temperatures.
Food and feeding habits
Pacific bonito prey on smaller pelagic fish, as well as on squid and shrimp, generally in surface waters. Anchovies and
sardines appear to be their preferred foods.
Other Names
California bonito, eastern Pacific bonito, bonehead, Laguna tuna,
striped tuna, ocean bonito; French: bonite du Pacifique; Japanese: hagatsuo; Spanish: bonito del Pacífico.
Distribution
Pacific bonito occur discontinuously from Chile to the Gulf of Alaska. Their greatest area of abundance occurs in the Northern Hemisphere in warm waters between Magdalena Bay, Baja California, and Point Conception, California.
Habitat
Bonito live in surface to middle depths in the open
sea and are migratory. Older fish usually range farther from the coast than do juveniles. Bonito may arrive off the coast in the spring as
ocean waters warm, but they may not show up at all if oceanic conditions produce colder than normal temperatures.