ニ and so on are river crabs, such as Jiujiang and Wuhu.
The third class is the river crab.
The fourth class is the crab.
The fifth class is the ditch crab.
The sixth class is sea crabs.
river crab
1, Eriocheir sinensis: Eriocheir sinensis, a crustacean, taxonomically belongs to Arthropoda, Crustacea, Cladocera.
It breeds in seawater, grows in fresh water, likes to dig holes and live, and often hides on the banks of rivers and lakes and marshes, or hides in gravel and water grass.
Stone crab
2. Stone Crab: Stone Crab, also known as Gexie and Xiexie, is a freshwater and brackish crab, crustacea,+poda, potamidae, inhabiting beside streams or under rocks in streams.
blue crab
3. Blue crab: The scientific name of the blue crab is Scylla serrata. The carapace of the blue crab is oval, flat and hairless, with developed head and chest, strong pincers and hind feet, so it is known as a scorpion.
Sea crab
4. Flower crab: Flower crab is also called Portunus pelagicus. Its head breastplate is about twice as wide as its length, and it is spindle-shaped with rough particles on its surface. The particles of females are more significant than those of males.
The forehead has 4 teeth, the middle 1 pair of frontal teeth is shorter and smaller, the adult is sharper, and the larva is more rounded and blunt.
The front side edge has 9 sharp teeth, and the last teeth are much larger than the previous teeth and protrude to both sides.
swimming crab
5. Portunus: Portunus is named because its breastplate is shaped like a shuttle.
There are three protrusions in the center of the carapace, so it is called Portunus trituberculatus.