The Herpetological Journal

pp. 43-47
Authors: Vrcibradic, Davor; Rocha, Carlos Frederico D. & Rocha-Barbosa, Oscar

Abstract: Little information exists on the allometric relationship between body mass and snout-vent length (SVL) in lizards, in spite of the relevance of that relationship for the understanding of morphological and ecological parameters. In this study we analyzed the mass-SVL relationship for three Brazilian scincid species (Mabuya agilis, M. macrorhyncha and M. frenata). Our results were indicative of negative allometry for both sexes in all three species, suggesting a general tendency for a relative reduction in bulk as the animal grows. The slopes and intercepts of the regression line did not differ between the sexes in any of the species, except M. macrorhyncha, in which the intercepts differed (suggesting that females would tend to be relatively less robust than males). When the analyses were repeated including juvenile individuals (previously excluded from the data set), the regression for M. agilis tended towards isometry, though it did not change for the remaining species. The results of the present study differ from those found for other Scincidae (including the congener M. heathi), which generally tended towards isometry or positive allometry. We also indicate that mass-SVL regressions may give different results for the same lizard species, depending on whether immature specimens are included or not in the analyses.

Keywords: GROWTH, ALLOMETRY, BRAZIL, SCINCIDAE