Use Figure 6 to assist you in determining if your specimen is a male or a female. Position the crayfish dorsal side up. Open the stomach and locate the chitinous teeth that form the gastric mill which is used to grind food. The intestine runs from the stomach through the abdomen ending at the anus. The large yellowish digestive gland, which secretes enzymes and stores food, occupies much of the area lateral and posterior to the stomach.
Testes are generally white and ovaries orange.
Sperm from the testes exit the body through a pore at the base of the fifth pair of walking legs, and eggs are released at the base of the third pair of walking legs. During reproduction, males and females copulate and sperm cells are passed to the genital openings of the female.