Narrow-Clawed Crayfish – Anatomy

The body of this crustacean is divided into two main parts: the cephalothorax, which consists of the head and thorax, and the flexible abdomen. The body is covered by a hard exoskeleton that protects the vital organs and part of the head. On the head, there are independently moving eyes and two sets of antennae used for gathering sensory information. Strong mandibles are also present, opening side to side. The thorax has four segments, each with a pair of walking legs. The digestive system of the crayfish includes a two-part stomach: the cardiac stomach and the pyloric stomach. Flanking the pyloric stomach are two digestive glands that aid in digestion. The crayfish’s excretory structures, known as green glands, function in a manner similar to kidneys. Its vascular system lacks veins, and the ventral nervous system consists of a mass of nerve ganglia (often referred to as the brain), which connects to the eyes and antennae. Two main nerves extend from the brain, forming the ventral nerve cord, which runs the length of the abdomen.