Ovarian development in sexual and parthenogenetic geckos of the Heteronotia binoei complex

Abstract

Ovarian development in sexual and parthenogenetic geckos of the Heteronotia binoei complex was analysed quantitatively by gross and histological examination. Females were classified into one of four stages of the reproductive cycle: non‐reproductive, preovulatory, postovulatory and postoviposition. Parthenogens had significantly more developing follicles present in the ovaries than sexual females in non‐reproductive, preovulatory and postovulatory stages of the reproductive cycle. The larger number of developing follicles in parthenogenetic Heteronotia was correlated with the significantly larger body size of the parthenogenetic females at the localities examined. Maximum follicular size and rates of follicular atresia were not significantly different between sexual and parthenogenetic females. These findings raise the possibility that the reproductive output of the parthenogenetic females may be higher than that of sympatric sexual females at these localities due to an increase in follicular recruitment. Based on this evidence, we predict that at these localities parthenogenetic females produce more clutches of two eggs than sexual females. If viability is equal, this would enhance the reproductive advantage of parthenogens over the two‐fold level already present. In all other respects, the morphology of the ovaries appeared very similar between parthenogenetic and sexual females and was typical of geckos.