1, the crab has eight legs, one on each side of its body, and the crab's big pliers are not crab's legs. A normal crab has a pair of pincer-like feet, which are used to dig holes, defend and attack, and are called pincer feet. The other four pairs of feet are used for walking or paddling, which are called walking feet.

2. The function of pincers and walking feet is different, so strictly speaking, crabs should have eight walking legs and two pincers without walking function. Crab's body is divided into head, chest and abdomen. There will be breastplates on the back of the head and chest, with different shapes and certain differences. There are 1 and 2 pairs of antennae in the center of the forehead, and compound eyes with stalks on the outside. The mouthparts include 1 pair of big jaws, 2 pairs of small jaws and 3 pairs of jaws. There are five pairs of chest feet on both sides of the head breastplate. The abdomen degenerates, flattens and bends on the ventral surface of the head and chest.