Bonito Tuna are the smallest and most abundant of the major commercial tuna species. They have a streamlined body that is mostly without scales. Their backs are dark purple-blue and their lower sides and bellies are silver with four to six dark bands. Bonito Tuna can live as long as eight to 10 years. They are found mainly in the tropical areas of the Atlantic, Indian and Pacific Oceans, with the greatest abundance seen near the equator. Bonito Tuna or Skipjack usually swim near the surface at night and can dive up to 850 feet during the day. Large schools of adult skipjack tuna or Bonito often mix with juvenile yellowfin and bigeye tuna. They can breed year-round.
Distribution of the Bonito Tuna
Again, each species has its own unique distribution and range. Some live in the Atlantic, some utilize the Indo-Pacific region, and some live in virtually any temperate or tropical sea worldwide. Their ranges extend from the northern and southernmost temperate seas, through subtropical waters, and into tropical regions.
Diet of the Bonito
All of the various species have carnivorous feeding habits. Voracious and opportunistic, these hunters actively pursue and catch just about anything that will fit in their mouths. Common prey items include squid and small fish such as anchovies. Though their prey varies based on the species and the size of the fish at hand.
Behavior of the Bonito Tuna
The social behavior of each species varies, though most show some degree of schooling behavior. Some species prefer living in small groups, while others school in large numbers. All species have high activity, and swim constantly in search of prey. Many species also live close to the surface of the water, and congregate in schools closely associated with seagulls.
Reproduction of the Bonito
Each species has its own unique reproductive behavior. As a whole, this group breeds via spawning, where the females release their eggs into the water and the males fertilize them outside of the body. Different species and different sized females produce different numbers of eggs. The eggs and larva both float freely in the water column. For more information about Bonito, please click here!