The skipjack tuna ( Katsuwonus pelamis) is a perciform fish in the tuna family, Scombridae, and is the only member of the genus Katsuwonus. It is also known as katsuo, arctic bonito, mushmouth, oceanic bonito, striped tuna or victor fish. It grows up to in length. It is a cosmopolitan pelagic fish found in tropical and warm-temperate waters. It is a very important species for fisheries.
Skipjack tuna are batch spawners. Spawning occurs year-round in equatorial waters, but it gets more seasonal further away from the equator. Fork length at first spawning is about . It is also known for its potent smell.
Skipjack tuna has the highest percentage of skeletal muscle devoted to locomotion of all animals, at 68% of the animal's total body mass.
Skipjack tuna are highly sensitive to environmental conditions and changes. Climate change effects are significant in marine ecosystems, and ecological factors may change fish distribution and catchability.
Skipjack is the most fecundity of the main commercial tunas, and its population is considered sustainable against its current consumption. Its fishing is still controversial due to the methodology, with rod and reel or fishery options being promoted as ecologically preferable.
Purse seine methods are considered unsustainable by some authorities due to excess bycatch, although bycatch is said to be much reduced if fish aggregation devices are not used. These considerations have led to the availability of canned skipjack marked with the fishing method used to catch it. As much as 95% of skipjack tuna catches may be used as canned tuna.
Skipjack is considered to have "moderate" mercury contamination. As a result, pregnant women are advised against eating large quantities. In addition, skipjack's livers were tested globally for tributyltin (TBT) contamination. TBT is an organotin compound introduced into marine ecosystems through antifouling paint used on ship hulls and has been determined to be very toxic. About 90% of skipjack tested positive for contamination, especially in Southeast Asia, where regulations of TBT use are less rigorous than in Europe or the US.
The fish's fat content changes during migrations along the Japanese islands. When they migrate north in summer, they are called hatsugatsuo ("first katsuo") or noborigatsuo ("ascending katsuo"), and have a lesser amount of fat. When they migrate south in autumn, they are called modorigatsuo ("returning katsuo") or kudarigatsuo ("descending katsuo"), and have a high level of fat.
Skipjack tuna is an important fish in the native cuisine of Hawaii (where it is known as aku) and throughout the Pacific islands. Hawaiians prefer to eat aku either raw as a sashimi or poke or seared in Japanese tataki style.
The trade in pickled skipjack tuna is a driving force behind the commercial fishery of this species in Spain.
Fisheries
As food
Japan
Other places
Sources
External links
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