The Role of Hibernation on Testicular Cycle and Testicular Activation During Dormancy in Nature in Hibernating Lizards

Nasrullah Rastegar-Pouyani, Farhang Torki


The testicular cycle in lizards, inhabitant of the temperate regions showing regeneration and degeneration periods during the year. For study of testicular activation in lizards, inhabiting in a temperate region, the specimens of ground agamid, Trapelus lessonae, were collected in Lorestan Province, western Iran. During the hibernation period, testes of the collected specimens were removed and treated using standard histological processes and techniques. Based on our studies, two phases of testicular activity were observed during the hibernation period as follows: (1) a relatively silent phase occurred during the early hibernation according to which testicular tissue slightly increased and (2) an activation phase occurred in late hibernation period in which the testicular tissue strongly increased. Based on this study, the testicular activation in temperate regions occurs during the late hibernation period and that the hibernation period has an important role to renewing the testicular tissue in the hibernating lizards and this is a very good instance of natural selection in action.


hibernation; testicular cycle; testicular activation; temperate regions; lizards; Trapelus lessonae

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