Bass head is large and flat, snout is sharp and flat, and eye area is wide and slightly concave. The mouth is very big, and the lower jaw protrudes slightly from the upper jaw and then extends below the eyeball. Because the front looks like an old man, and the fish sounds like an old man's cough, it is nicknamed "old fish"

Perch likes to live in still water of small tributaries of rivers, or in swamps with many aquatic plants. The water level is generally 30 ~ 60 cm, and there are many humus deposits at the bottom of the water. The suitable temperature range is wide, and it can survive in the range of 15 ~ 30℃.

Lateolabrax japonicus is inactive and does not travel far. It can survive in extreme hypoxia and has strong wintering ability. When the water surface freezes, perch-beaked fish often live in hemispherical ice caves, the diameter of which is generally 20-200 cm, and the top of the ice cave is about 30-60 cm away from the ice. The hole is located in the water, and there are often dense aquatic plants below. The cave is filled with small ice cubes and air, and the temperature is close to zero. When the ice surface is broken, the perch is directly dragged out of the ice cave.

Perch and pond fish are carnivorous fish, and there are many plankton and benthos in the waters. Because of their poor swimming ability, they often attack weak animals that used to eat in a latent way. The common prey of perch Eriocheir sinensis includes red nematodes, water worms, leeches, grub larvae, shellfish, various aquatic insects larvae and fish eggs, and larger individuals can also swallow young fish.