Crawfish is shrimp. The scientific name of crayfish is Procambarus clarkii, also known as red crayfish or freshwater crayfish, which belongs to arthropods and lives in fresh water. Crayfish feed on aquatic plants, algae, aquatic insects and animal carcasses, and kill each other when food is scarce. It is a fresh water economic shrimp with delicious meat and an important economic variety in China. Lobster is shaped like a shrimp with a hard shell. The adult is about 5.6~ 1 1.9 cm long, and the overall color is red, reddish brown and pink. Dark red on the back, pink on both sides, with orange or white spots. Some crustaceans are almost black with wedge-shaped stripes on the back of the abdomen. Larvae are all gray, sometimes with black ripples. Narrow pliers. The middle part of the carapace is not separated by a mesh gap, and there are obvious particles on the carapace. The frontal sword has a side thorn or the end of the frontal sword has a notch. Claws are dark red and black with bright orange or red nodules. The background color of larvae and female claws can be dark brown. The tip is long and often has slight thorns or nodules. Nodules usually have spikes.