Atlantic bluefin tuna (scientific name: Thunnus thynnus): it is a marine animal of tuna, mackerel and tuna. The body length can reach 3 meters and the weight is about 400 kilograms. Generally, tuna fishing boats catch about 150 kg, and more than 200 kg is a bumper harvest.

The largest recorded individual was captured in Nova Scotia, Canada, weighing 679 kg. The body is spindle-shaped, strong and nearly oval in cross section. The snout is conical, the mouth is large, and the maxilla extends backward to the middle and lower part of the lower eyelid.

The tail stalk is thin, with 1 large ridge and 2 small ridges on both sides. The body is covered with small round scales, and the chest scales are very large, forming a breastplate. There are two dorsal fins, which are very close. The pectoral fin is short and ends in the middle of the first dorsal fin. Separation of apical process of ventral fin.

There are 8- 10 small fins behind the second dorsal fin and gluteal fin, respectively. The caudal fin has a crescent-shaped blue-black back, a silvery white abdomen and a black caudal stalk ridge. The first dorsal fin is yellow or blue, the second dorsal fin is reddish brown, and the gluteal fin and free fin are dark yellow with black edges.