The effect of temperature on the male reproductive system of the common water snake (Nerodia sipedon)

Abstract

AbstractThe effect of various temperatures upon the male reproductive cycle of the common water snake (Nerodia sipedon) was studied. Snakes were divided into five groups and kept at five different temperature regimes and a 0L:24D photoperiod for ten weeks. Those kept in Chamber 1 were at 20°C the entire day while those kept in Chambers 2–5 were maintained at 21.3, 23.3, 27.4 and 29.3°C for eight hours per day respectively and 20°C for the remaining 16 hours each day.Interstitial cell nuclear diameters, renal sexual segment tubule diameters and epithelial heights were found to be unrelated to increasing temperatures. Testicular growth was positively correlated to increasing temperatures. Seminiferous tubule diameters increased rapidly between 20 and 21.3°C with a Q10 = 39. Tubule diameters continued to increase, although at a slower rate, with further increases in temperature, with a Q10 = 1.72 between 21.3 and 29.3°C. Spermatogenesis increased with increasing temperatures; the threshold temperature for initiation of spermatogenesis was between 20 and 21°C.Therefore, spermatogenesis and testicular recrudescence in Nerodia sipedon are temperature and not light dependent. Further, this report shows that weight of fat bodies does not affect normal spermatogenesis and testis growth in the presence of a sufficient food supply.