Its appearance is spindle-shaped and its skin is smooth. The fins are streamlined, and the colors of the two dorsal fins are different. The first dorsal fin is dark yellow, the second dorsal fin is light yellow, and the tail handle is thin and flat. The pectoral fins on both sides are very long, the position of the back will be dark blue and bright, and the edge and abdomen of the fish will be silvery white.
Living habits
Migratory fish in the middle and upper ocean. Mainly active in the waters below the thermosphere, the habitat depth can reach 600 meters. The constant water temperature is about 17℃-2 1℃ (minimum 9.5℃). Due to the change of water temperature, it is often vertically distributed. It feeds on migratory small fish, such as mackerel, and also preys on crustaceans and cephalopods.
Foods include saury, anchovies, crustaceans, squid and Japanese anchovies, and their eating habits change seasonally with different regions. At any time, anchovies account for 96% of their food sources. Studies have found that albacore tuna will attack scattered anchovies and swim vertically in the water day and night to catch up with prey.
Natural enemies: sharks, rays, manta rays, big tuna and beaked fish.