Análise morfométrica em cinco espécies do gênero Mabuya Fitzinger, 1826 (Squamata : Scincidae)

Abstract

The present study has as its main objective to analyse the ontogenetic variation of body shape in the South American skinks Mabuya agi/is Boulenger, 1887; M. bistriata (Spix, 1825); M. guaporicola Dunn, 1936; M. rnacrorhyncha Hoge, 1946 and M. nigropunctata (Spix, 1825). Interspecific differences of body proportions as a possible result of allometric growth in these species are also examined. PCA analysis was used for estimate the both ontogenetic trends and allometric growth. Ontogenetic trend lines were significantly different between M. guaporicola and the others species, and between M. bistriata and M. nigropunctata. Ali of the other pairs showed significantly different Y intercept between each other. Analysis of the allometric coefficients indicates that relative reduction of limbs associated with body elongation in Mabuya guaporicola are due to the reduction of its hands, feet and specially digits; M. rnacrorhyncha presents a high and stout pectoral girdle and its hands show an accentuated reduction; in M. bistriata, its arms are relatively short and its thigh and tibia elongate. M. nigropunctata is the species which the least modified body shape during ontogeny. The association of these results with data on habitats utilized by each species (obtained from the literature) indicates that some morphological specializations found in each species could be explained as functional adaptations to their habitats.