1. crayfish:

1. 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 nearly black carapace and wedge-shaped stripes on the ventral back. Young shrimps are evenly 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 frontal sword has a lateral thorn or a notch at the end of the frontal sword.

2. It is a kind of 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. Its feeding range includes aquatic plants, algae, aquatic insects and animal carcasses. When food is scarce, they also kill each other. In recent years, crayfish has become an important economic species in China. In the process of commercial farming, it is necessary to prevent escape, especially to enter untouched original ecological water bodies. It has caused devastating damage to the ecological competitive advantage of local species.

2. Morphological characteristics: Crayfish looks like 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. The back is sauce red, and the sides are pink with orange or white spots. The shell is nearly black, and there is a wedge stripe on the back of the abdomen. Young shrimps are evenly 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 frontal sword has a lateral thorn or a notch at the end of the frontal sword. Claws are dark red and black with bright orange-red or red nodules.