Crayfish / Crawfish / Crawdads Morfology / Anatomy

Crayfish (also known as crawdads, crawfish, mudbugs, or yabbies), are common throughout the world. There are  over 400 difference species of crayfish, 330 of which are native to the United States. Crayfish are commonly used  as food, bait,

Anatomy, Geographical Distribution and Classification

The body of a decapod crustacean, such as a crab, lobster, or prawn, is made up of twenty body segments grouped into two main body parts, the cephalothorax and the abdomen. Each segment may possess one pair of appendages, although in various groups these may be reduced or missing. On average, crayfish grow to 17.5 centimetres (6.9 in) in length, but some grow larger.

There are three families of crayfish, two in the northern hemisphere and one in the southern hemisphere. The southern-hemisphere (Gondwana-distributed) family Parastacidae lives in South America, Madagascar and Australasia, and is distinguished by the lack of the first pair of pleopods. Of the other two families, members of the Astacidae live in western Eurasia and western North America and members of the family Cambaridae live in eastern Asia and eastern North America.