Reproductive, Fat, And Liver Cycles Of Male And Female Rose-Bellied Lizards, Sceloporus variabilis, From Coastal Areas Of Southern Veracruz, Mexico

摘要

We studied the reproductive cycles of 350 male and female Sceloporus variabilis from coastal areas of the Gulf of Mexico, Mexico, that exhibited continuous reproduction. Males reached sexual maturity at 45 mm snout-vent length (SVL), whereas females reached sexual maturity at 44 mm SVL. Testicular mass varied among months. Testes began to increase in size during April, with maximum sizes reached from May to July. Maximal testicular growth was positively correlated with increasing temperature and photoperiod, but not with precipitation. Females contained vitellogenic follicles and oviductal eggs throughout the year, although maximal egg production occurred from June to January. Forty-two females (40%) had vitellogenic follicles and oviductal eggs simultaneously. Mean clutch size, based on vitellogenic follicles, was similar (mean = 3.7 plus or minus 0.17 SE) to that observed by counting oviductal eggs (mean = 3.7 plus or minus 0.10 SE). Females with a SVL greater than or equal to 51.5 mm plus or minus 0.91 SE had at least 2 clutches. Clutch size was correlated with female SVL. Differences in reproduction found in this study compared with other populations of the same species might be explained by environmental differences at the study sites.