This kind of fish is the jaw needle fish, also known as the green needle fish and the long-billed fish. Edible, bones are naturally green. Its shape is similar to hairtail. Long cylindrical, slightly flat, with a body length of about 1 m and a weight of1.50g-300g. The most obvious feature is that the maxilla and maxilla are prominent, sharp and long. Some fishmongers lied that it was tuna to raise the price. It is understood that the market price of toothfish is only 4 yuan -5 yuan per catty.

The real tuna is round, like a "torpedo", with a dark gray surface, and its shape is obviously different from that of needlefish.