Análise da variação geográfica em lagartos (Reptilia: Squamata) de seis áreas da Amazônia Brasileira ao sul do Rio Amazonas

Abstract

The group of lizards belongs to the order Squamata, with about 4450 species, distributed among almost 450 genera. Of this total, 89 species occur in the Brazilian Amazon. Studies show an east-west faunal division of these species on the south bank of the Amazon River. The present study aims to verify the existence of geographic variation in seven lizard species (Ameiva ameiva, Anolis fuscoauratus, Anolis punctatus, Cercosaura ocellata, Gonotodes bumeralis, Mabuya nigropunctata and Plica umbra ochrocollaris) from six localities south of the Amazon River, located along an east-west transect. We studied (1) standard scalelation characters for each species, with scales counted under a stereomicroscope; and (2) morphometric characters, measured with a digital pachymeter, when possible using measurements made in the field, before fixation of the specimen. We analyzed 106 specimens of Ameiva ameiva, 102 of Anolis fuscoauratus, 34 of Anolis punctatus, 48 of Cercosaura ocellata, 35 of Plica umbra and 93 of Mabuya nigropunctata. Vitt et. al. (2003, Can. J. Zool. 81:142-156), analyzing Anolisfuscoauratus at different localities in the Amazon, found morphometric differences, demonstrating that different populations undergo geographic variation. Such a conclusion, however, for meristic data, still needs to be confirmed for Anolis fuscoauratus, as also verified for the other species in the study. The statistical analyses that will answer these questions are still in progress.