The anatomy of the male genital system of the beluga whale, Delphinapterus leucas, with special reference to the penis.

The genital organs of four male adult beluga whales and one newborn animal were dissected and the main characteristics are described. As in other species of cetaceans, the testes and the greatest part of the penis are located inside the abdominal cavity. The penis has a sigmoid flexure and belongs to the fibroelastic type with a thick tunica albuginea and a small amount of vascular spaces in the erectile tissue. The prostate gland, found in other cetaceans, was not seen macroscopically, but only small prostate rudiments could be identified histologically. The os penis and the other accessory glands are absent as in other whales.