The Relation between Preferred Body Temperatures and Testicular Heat Sensitivity in Lizards

The range of temperatures preferred by each species appears to be critically adjusted to a level compatible with the maximum tolerable temerature for the testes. However, continuous exposures even to preferred temperatures may be detrimental to both reproductive and somatic tissues. Loss of appetite and weight at high temperatures indicates a general systemic disorder, and spermatogenic failure may result from this rather than from heat per se. The lizards' use of high temperatures is evidently restricted by both systemic and reproductive heat sensitivities.