INTERSEX RED CLAW CRAYFISH, CHERAX-QUADRICARINATUS (VON MARTENS) - FUNCTIONAL MALES WITH PRE-VITELLOGENIC OVARIES

Intersex individuals, possessing both male and female genital openings , were assessed in two groups-7 and 19 months old-of Australian red cl aw crayfish (Cherax quadricarinatus). All intersex individuals investi gated were functional males, as suggested by their male-like morpholog y and the presence of testes, sperm ducts, androgenic glands, and viab le spermatozoa. When an ovary was present in an intersex individual fr om either group, the gonadosomatic index, the diameter of the oocytes, and the ovarian cytosolic polypeptide profile were similar to those o f immature, pre-vitellogenic females. We conclude that intersexuality in C. quadricarinatus does not indicate a case of protandric sequentia l hermaphroditism, as previously suggested. The case of intersexuality described here presents a unique model for the study of the role of t he androgenic gland in the regulation of sex differentiation in crusta ceans.