The fish body is spindle-shaped, with a silvery-white abdomen and 4 to 10 dark gray stripes below the lateral line. The average body length is about 80 cm and the weight is about 8 to 10 kg. The maximum body length can reach 100 cm and the weight is about 30 kg. Distributed in tropical and temperate waters of the three oceans. Bonito often gather in surface waters, and the schools of fish are often accompanied by floating objects, whales, sharks or other tunas, and are characterized by jumping, foraging and producing foam on the sea surface. Due to its schooling characteristics, it has become the main target of purse seine fishing. In terms of the catch composition of large-scale purse seine fishing in my country, skipjack tuna accounts for about 75% and yellowfin tuna accounts for about 25%.