There are about 30 species in 16 genera and 30 species in the family of pond fish (táng, lǐ). It is found along the coast and in the middle and lower reaches of major rivers. Common genera are Wutang snakehead, pond snakehead, sand pond snakehead, saw pond fish, Meitang snakehead, perch and so on. Pond fish are small edible fish, some species of meat tender, delicious, such as the Chinese Wutang fish produced in the South China Sea and the Taiwan Strait, high nutritional value, is a valuable tonic. Sharp-headed pond snakeheads are found in The Minjiang, Pearl and Taiwan rivers of China. Shatang snakehead is produced in China's Yangtze River, Pearl River, Qiantang River, Minjiang River and Taiwan to the northeast.
Most of the species living in seawater inhabit coastal shoals, gravel, seaweed or coral bushes; some burrow in caves; pond snakes inhabit offshore coasts, estuaries and fresh water, and most of the species living in the ocean inhabit coastal shoals, gravel, seaweed or coral bushes, and some burrow in cave dwellings; Species that live in freshwater inhabit the bottom layers of lakes and rivers and shallow waters on the shores where sediment, gravel and weeds are mixed. It feeds mainly on shrimp, small fish and benthic animals, and freshwater pond fish also eat aquatic insects. The spawning period is generally spring, and some species have nesting and egg protection habits. Pond fish are generally 80 to 160 mm long. Larger species such as the African Udon snakehead can reach a length of up to 210 mm.
The body is elongated, flattened or stout laterally, subcylindrical. The head is flattened or flattened laterally. The eyes are large or small, do not protrude from the back of the head, and do not have free eyelids. The lower jaw is often protruding. The upper and lower jaws have fine teeth, and the palate is often toothless. The edge of the anterior gill cap has a small or spineless margin that curves downwards anteriorly. The body is scaled and the head is often covered with small round scales. No sidelines. The first dorsal fin has 6 to 8 spines, the second dorsal fin has 1 fin spine and 8 to 10 fin strips. The fin is conformed to the second dorsal fin. The pectoral fin is large and the base is not stalk-shaped. The ventral fin is pectoral, with 1 fin spine, 5 fins, and the left and right ventral fins are close to each other, separated from each other, and do not form suction cups. The caudal fin is rounded or slightly pointed.