Reproduction and sexual dimorphism of Lepidophyma sylvaticum (Squamata: Xantusiidae), a tropical night lizard from Tlanchinol, Hidalgo, Mexico

Abstract

We studied reproductive characteristics of the night lizard, Lepidophyma sylvaticum (Xantusiidae) from cloud forest in Tlanchinol, Hidalgo, Mexico. Males reached sexual maturity at a snout-vent length (SVL) of 55 mm, and females reached sexual maturity at a SVL of 56 mm. Males and females were not sexually dimorphic in SVL, but males had significantly larger heads and limbs than females. Reproduction in males and females was seasonal. Testicular mass increased in July and August, reaching maximum size in September. Minimum testes size occurred in March. Follicles of females began to increase in size in September when vitellogenesis was observed. Follicles in some females increased in mass during January-March, whereas other females ovulated during that period. Late embryonic stages (35-40) were observed in July with parturition likely occurring in July and August, coincident with maximum rainfall. Litter size averaged 4.7 ± 0.4 neonates, and was not correlated with female size. Similarities in reproductive characteristics between L. sylvaticum and other xantusiids (viviparity, long gestation period) suggest that some reproductive characteristics have a historical origin. © 2008 Brill Academic Publishers.