Crayfish: also known as Procambarus clarkii, red crayfish and freshwater crayfish. Shaped like a shrimp with a hard shell. The adult is about 5.6~ 1 1.9 cm long, dark red, with a nearly black shell and a wedge-shaped stripe on the back of the abdomen. Young shrimps are uniform gray, sometimes with black ripples. Long and narrow claws. The middle part of the carapace is not separated by a mesh gap, and there are obvious particles on the carapace. The forehead sword has lateral spines or the end of the forehead sword is scored.
Extended data:
Crayfish are cultured all over the world and form a huge wild population. China was introduced from Japan in 1930s and 1940s, and Japan was introduced from the United States earlier, mainly used as food and pets. Crayfish are often mixed in crops (such as rice). There is no need for artificial incubation. Once the original seed is put into the pond, it can achieve self-maintenance. After harvesting, it is not necessary to put the original seed again. Escaped individuals dug holes in the dam to survive.
Because of its strong adaptability, strong resistance, wide feeding habits and fast population proliferation, crayfish often cut crops, especially rice crops, and may compete with local crayfish species.
Baidu encyclopedia-crayfish