Estudo da relação entre aspectos morfológicos da língua de dezesseis espécies de lagartos ocorrentes no brasil e seus respectivos tipos de forrageio

Abstract

The Squamata reptiles have a sophisticated sensory system, frequently adapted to the environment in which they live and the activities performed in their foraging. The tongue lizards is a fundamental structure of the sensory system for foraging. Thus, this study sought investigate the morphological and histological tongue structure of 16 species of Brazilian lizards and its relationship with ambush and active foraging. For that, were analyzed the shape and elongation and made histological slides of tongues specimens of the 16 species and colored by HE, PAS, Alcien Blue and Gomori Trichome. Scanning electron microscopy of the tongue of 13 species was made. The tongue of all species showed stratified squamous keratinized epithelium, with the keratin layer varying in thickness and position in the tongue also sacle-like papillae, filiform papillae. Teiidae and Gymnophtalmidae lizards showed the most specialized tongue and restricted to wile foraging, while Leiosauridae, Gekkonidae, Polychrotidae and Tropiduridae lizards presented tongue with less favorable to “tongue-flicking” and therefore closest to ambush foraging structure. Mabuyidae and Anguidae lizards species showed characteristics of both foraging types, showing a probable plasticity between the extremes of wile and ambush foraging. This fluctuation between types of foraging has been observed within the old genus Mabuya from previous studies that indicate that factors such as food availability and habitat changes are able to alter the dynamics of some species foraging. In this study it was possible to relate aspects such as types of papillae, tongue shape, muscular arrangement, keratin layer, among others, with the possible dynamics of foraging the 16 species. The muscle arrangement found in active foragers was considered more compact and focused for the “tongue-flicking”, while the ambush foragers muscle arrangement shown less restricted. And stand out from other factors such as the presence of taste buds. The analysis of external and microscopic characteristics of the tongue provided great contributions to the understanding of how the lizard optimizes its environment perception, as realize the time and its energy expenditure. Also contributes with more information about the morphology and ecology of species occurring in Brazil.