The pufferfish (Tetraodontidae; pufferfishes), commonly known as pufferfish, is the collective name for fishes of the family Pufferidae of the order Scleractinia. River puffer body is cylindrical, with the well-known round body, general body length of about 100 to 300mm, large up to 630mm or more. The upper and lower jaws are fused with teeth to form four large plates, and the body length can reach 1.1 M. There is one dorsal fin and no ventral fin. No scales or small spines. It has air sacs that can inhale and expand. There are many species, most of which live in the sea, but can also be found in freshwater and at the confluence of sea and freshwater. They blow water and air through the water, causing sediment to fly up and then prey on creatures hiding in the sand. Because the teeth and jaws are hard, they can bite even extremely hard shells. The whole is oval, bluntly rounded in front and tapering at the tail. The muzzle is short, rounded; the mouth is small, terminal, and transverse. Upper and lower jaws each with 2 plate-like incisors, with a distinct mesial suture. Lips well-developed, both ends of lower lip curved upward on outer side of upper lip. Eyes small, gill pores small, a curved slit, located in front of the pectoral fins, body surface densely covered with small spines. Dorsal fin very posterior to anal fin; no ventral fin; caudal fin flat-truncated at posterior end. The dorsum of the body is grayish-brown, the sides of the body are slightly yellowish-brown, and the ventral surface is white; the markings on the dorsum and sides of the body vary with the species.

The river herring is a warm-temperate and tropical offshore demersal fish, inhabiting the middle and lower layers of the ocean, with a few species entering freshwater rivers, and when encountering external dangers, they make their whole body float up to the surface in the shape of a ball, and at the same time the small spines on their skin stand up to defend themselves. The common ones are Takifugu rubripes, T. fasciatus, Lagocephalus inermis, Chelonodon patoca, and Aronthron nigropunctatus.