Crayfish (scientific name: Procambarus clarkii): 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.

It is a freshwater economic shrimp, which is widely welcomed by people because of its delicious meat. Because of its omnivorousness, fast growth and strong adaptability, it has formed an absolute competitive advantage in the local ecological environment.