What is the purpose of pincers on a crab?
Crabs have two claws, which are also called "pincers" or "chela".  Their pincers allow them to capture their prey, cut their food, and fight off predators. Their claws are different sizes; the larger claw serves as a crushing mechanism and the smaller claw as a cutting instrument.  Crabs like to fight with each other, and by using their claws they can break the leg of their opponent to weaken them. 