Crabs have a total of 10 legs that help the crab move around and walk around
The crab has 10 paired legs and the front two legs are the claws and the swimming crab such as the flying crab has two flattened, back legs used as paddles for swimming.
Many crabs also can only walk sideways, but not all of them.
Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail", usually hidden entirely under the thorax.
Crabs live in all the world's oceans, in fresh water, and on land, are generally covered with a thick exoskeleton, and have a single pair of pincers.
Crabs are also eaten by Sea Anemone.
As for the lifespan of a crab the lifespan of the crab varies depending on the species of the crab and some crabs live only 8 years while some crabs can live as long as 30 years and even up to 70 years if the crab is not eaten.