Biologia reprodutiva do lagarto Teiú, Salvator merianae (Duméril & Bibron, 1839) (Squamata, Teiidae)

Abstract

Tropical lizards have a great diversity of reproductive patterns influenced by environmental factors. Reproductive cycles may be mouldable in tropical areas, mainly due to climatic complexity. However, reproductive biology studies of lizards are more developed with species from temperate regions. Salvator merianae, popularly known as Tegu Lizard, is an oviparous, large (up to 1600 mm) diurnal animal, active and terrestrial forager, has the largest geographical distribution of its kind, occurring in 14 of 26 Brazilian states. Tegu Lizards are often seen exposed to the sun during the summer and in the cold months remain untouched and inactive for long periods (hibernation). Overall, Squamata have a wide variety of reproductive strategies that have evolved to meet environmental challenges. Although Salvator merianae is a well-known and widely distributed species, aspects of its reproductive biology are little explored. In this work the reproductive biology of males and females of the species Salvator merianae was investigated through morphological and histological analysis of Brazilian specimens. For this purpose, safeguarded specimens were evaluated in zoological collections with collections of vagina, ovaries, uterus and infundibulum tissues in females, as well as testes, epididymis, vas deferens and kidney in male specimens. Samples were processed for histological analysis (H/E) and observed under light microscopy (Olympus BX51). Most of the specimens have been collected in summer and spring, when they actively breed. The CRL of males ranged from 85.44 mm to 381 mm and females ranged from 88.61 mm to 342 mm. In immature males, the testis is characterized by seminiferous tubules without lumen. The smallest mature male was collected in the spring presenting the CRL (250 mm). This specimen was at the beginning of sperm and the KSS was not hypertrophied, probably because KSS had not yet received the testosterone hormone induction produced by the testis. The other male specimens presented testis in peak spermatogenesis, with sperm storage in the epididymis and vas deferens and hypertrophied KSS. In females, all were found in V1. Sperm storage receptacles were also observed in the posterior infundibles, but without the presence of sperm. Data regarding sexual dimorphism did not differ between male and female specimens.