Reproductive and Fat Body Cycles in the Male Lizard, Sceloporus undulatus, from Alabama, with Comparisons of Geographic Variation

Publisher Website
Google Scholar
Abstract
The testicular cycle of S. undulatus from Alabama was examined and compared to populations from Missouri and other areas. In Alabama males, the height of the breeding season (spermiogenesis and spermiation) occurred from March to May, accompanied by a decline in testis mass. Spermatozoa were present in the epididymides until July. During June and July, testis mass was minimal. A new spermatogenic cycle had begun by Aug. Testicular recrudescence occurred in fall with concomitant increase in testis mass. Seminiferous tubules contained many spermatids with a few transforming spermatozoa by the time lizards entered brumation. The timing of testicular events differs between northern and southern populations, likely reflecting regional differences in seasonal temperature regimes. Specifically, a longer warm season in Alabama apparently permits males to begin spermiogenesis and spermiation earlier and to complete fall recrudescence later than S. undulatus from Missouri. Fat body masses of Alabama S. undulatus increased in fall and decreased in spring soon after emergence from brumation. The loss of this stored energy is likely correlated with spring territorial and reproductive activities.