The Chinese mitten crab is also called river crab, hairy crab, clear water crab, hairy crab or crab.
Characteristics of green crabs:
The green crab has an oval-shaped carapace, flat and hairless body, developed cephalothorax, strong chelae and hind feet, shaped like anchovy, so it is called according to anchovy. The cephalothoracic armor is about 1.5 times as wide as long, and the back is elevated and smooth; the surface of the cephalothoracic armor has obvious "H"-shaped indentations; the forehead has four prominent triangular teeth, and the sizes and spacing of the teeth are roughly equal. Anterolateral margin with 9 prominent triangular teeth of similar size. Chelicerae smooth and asymmetrical, right foot slightly larger than left; palpal segment swollen and smooth, dorsum with 2 granular rondelles, each with 1 spine at its end. The first three pairs of pedipalps are edentulous, and the anterior and posterior margins of the phalanges are bristly with short hairs.
Body structure of the hairy crab:
The body is divided into two parts: cephalothorax and abdomen, with five pairs of footsteps. The back of the cephalothorax is covered by the cephalothoracic armor. Cephalothorax Chinese mitten crab dark green, square and round, looking down nearly hexagonal, the back half is wider than the front half, the central bulge, the surface is uneven, *** there are six protuberances for the ridges, frontal and hepatic concave drop, its anterior edge and the left and right anterior lateral edge *** there are 12 spines. The frontal region is flanked by a pair of compound eyes with stalks. The ventral surface of the cephalothoracic armor, except the anterior end for the cephalothoracic armor is wrapped, most of it is covered by the abdominal armor, which is divided into segments and surrounded by downy hairs, and the abdomen is immediately below the cephalothoracic part, commonly known as the crab umbilicus, which is surrounded by downy hairs, and **** divided into 7 segments. The female crab's abdomen is round, commonly known as the "umbilicus", and the male crab's abdomen is triangular, commonly known as the "umbilicus". The first pair of feet is prismatic, the end like a pincer, for the chelipeds, strong and densely tomentose; the fourth and fifth pair of feet is flat round, the end is sharp as a needle.
Body shape
Body nearly round, dorsal surface of cephalothorax is grass-green or dark green, ventral surface is grayish white, frontal margin of cephalothorax has 4 pointed denticles, anterior lateral margin also has 4 denticles, the 4th tooth is small and obvious. The abdomen is flat, ovoid to round in females and elongated bell-shaped in males, but the abdomen is triangular in both sexes in the juvenile stage, so it is not easy to distinguish between them. The chelicerae are used for feeding and resisting the enemy, and the inner and outer edges of their palps are densely covered with downy hairs, which gives the crab its name. 4 pairs of steppers are the main crawling organs, and the anterior corners of the end of the long segments each have a pointed tooth. Female abdominal limbs 4 pairs, located in the 2nd to 5th abdominal segments, two limbs type, densely setose, the inner limbs are mainly used to attach eggs. Male crabs have only the 1st and 2nd abdominal limbs, specialized as copulatory apparatus.