Scientific name of Eriocheir sinensis: Eriocheir sinensis, whose breastplate is square and the back is wider than the front. Its back is convex, and its forehead and liver area are concave. There are six symmetrical protrusions in front of its stomach area, and each protrusion has its own particles. There is a difference between the stomach area and its heart. There are pits around the former. Its forehead is wide and divided into four teeth. The upper edge of its eye socket protrudes in a triangle near the middle part. Its front edge has four sharp teeth, and the last one is the smallest. Along the inner side of the back edge, there are long claw feet, which are larger in males than females. The inner and outer surfaces of the metacarpal and phalangeal joints are densely covered with fluff, and the inner corner of the wrist joint has spikes, and the near end of the back edge of the long joint has spikes as the long joint for gait. The last three pairs of steps are flat, and the back edges of the wrist joint and the front joint have bristles respectively. Step 4, the back edge and abdomen edge of the forefoot joint and knuckle base are densely covered with bristles.

River crabs are also called "crabs" and "hairy crabs". The head breastplate formed by the combination of head and chest is square and hard. There are a pair of eyes at the front of the body and two pairs of very sharp crab teeth on the side. The appendage at the front end of the crab is called claw foot, and its surface is covered with fluff. There are 4 pairs of walking feet behind the claw feet, which are flat and long; The abdomen has degenerated. The sex of a river crab can be distinguished by its abdomen: the abdomen of a female crab is round, and that of a male crab is triangular.

Eriocheir sinensis is a large crustacean with a body divided into 2 1 segment. Because the head and chest segments are mutually healed, the whole body is divided into two parts: head, chest and abdomen. The back of adult crabs is dark, and the head and breastplate are 7 cm long and 7.5 cm wide on average.