River _, commonly known as "puffer fish", is the general name of teleost fishes. The river _ body is cylindrical, with airbags, and it will inhale and expand when it is in danger. Generally, its body length is 25-35 cm! The maxilla, mandible and dental callus were combined into four large dental plates, with dorsal fin 1 plate and no ventral fin. Scaleless or spiny. All oval, the front is blunt and round, and the tail is tapered. Kiss short, round and blunt; Small mouth, end position, transverse fissure. The upper and lower jaws have two plate-shaped incisors, and the middle seam is obvious. The lip is developed, and both ends of the lower lip are bent upward on the outside of the upper lip.
Small eyes, small gill holes, an arc-shaped crack, located in front of pectoral fin, densely covered with small thorns. The dorsal fin is very backward, opposite to the gluteal fin; No ventral fin; The rear end of the caudal fin is flat. The back of the body is grayish brown, the side is slightly yellowish brown, and the ventral surface is white; The markings on the back and side of the body vary with different species. There are many kinds, most of which live in the sea, but they can also be found in fresh water and the confluence of sea and fresh water.
They blow water and air in the water, make the sediment fly, and then prey on the creatures hiding in the sand. Teeth and jaws are hard and can crush extremely hard shells.
River distribution range
River _ is extremely rich in resources in China. There are 54 species along the coast of China, with an annual output of about 3-4 million tons, which can be caught in the coastal areas almost all year round. In the Yangtze River and Pearl River, the flood season occurs between spring and summer, which is one of the main fishery targets in the coastal areas and the middle and lower reaches of rivers. In our country, there are more than 30 kinds of rivers living from Liaoning to the coastal area of Guangdong, among which the dark orient enters the middle and lower reaches of the Yangtze River, Pearl River and other water systems.