Crayfish have five pairs of legs, for a total of 10. Four of these pairs are considered "walking legs," while the fifth pair are the "chelipeds" or pinchers.
Crayfish are members of the Arthropoda phylum, which means they have jointed legs, exoskeletons and segmented bodies. Except for the pinchers, which are larger, their legs are long and slender with multiple sections. The exterior skeleton is made from calcium-rich chitin, which is a substance similar to human fingernails. The body has two major parts. The cephalothorax, in the front, is followed by the abdomen. The first part is divided into the head and thorax regions. The abdomen, often referred to as the tail, has seven separate sections.