SPERMATOGENESIS IN THE LIZARD SCELOPORUS-MUCRONATUS (REPTILIA, PHRYNOSOMATIDAE)

Abstract

The annual spermatogenesis cycle of the lizard Sceloporus mucronatus from Acocomulco, Hidalgo, Mexico, was classified into seven stages. It has a long recrudescence period (6.5 months), starring during the winter with spermatogonial proliferation

the greatest number of primary and secondary spermatocytes occur in the spring and summer, respectively. During late summer and early fall the spermiogenesis takes place

the previous pattern defines a seasonal fall reproductive cycle, and the recrudescence is probably due to adaptative pressures controled by the neuroendocrine system. Populations reproduce in spring-summer or summer-fall. This results will help to understand the mechanism that regulates the fall reproductive season of temperate species inhabiting zones with tropical influence.