Sistematics and phylogeny of the genus Gymnodactylus Spix, 1825 (Squamata: Gekkota: Phyllodactylidae) based on morphological and molecular data

Author(s)

José Cassimiro da Silva Junior

• Document type: Doctoral Thesis
• Press: São Paulo.
• Institution: Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB)
• Defense date: 2010-08-31

Examining board members

Miguel Trefaut Urbano Rodrigues; Marcelo Rodrigues de Carvalho; Cristina Yumi Miyaki; Paulo Gustavo Homem Passos; Teresa Cristina Sauer de Ávila Pires

• Advisor: Miguel Trefaut Urbano Rodrigues

Abstract

The genus Gymnodactylus includes until now five species: G. amarali, widely distributed in the Cerrado biome (savannah) of central Brazil, G. darwinii restricted to Atlantic Rain Forest, from the northeastern São Paulo state to the limits of the Atlantic Rain Forest in Rio Grande do Norte state, G. geckoides, endemic to Caatinga, northeastern Brazil; G. guttulatus, known only from the campos rupestres (rocky meadows) from the north of the meridional segment of the Espinhaço range, and G. vanzolinii, recently described and known only from the Mucugê municipality, Chapada Diamantina, Bahia, north of the septentrional segment of the Espinhaço. In this study the genus was systematically reviewed based on morphological and molecular data. About 1,400 specimens from approximately 280 localities for 30 morphological characters, and, partial sequences of the genes RAG1, PDC (nuclear), 16S (ribosomal) and cyt b (mitochondrial), totaling 2,146 base pairs covering 25 localities were studied. For the molecular data, Maximum Parsimony analyses were performed using the program PAUP, and Bayesian inferences using MrBayes. Also, these genes were analyzed individually involving a more robust data set. Both independent analyses for each gene as well analysis combining only the nuclear genes were performed. The species recognition was mainly guided by the combination of genetic data and qualitative morphological characters, although distributional data and quantitative traits were also considered. Meristic data and morphometric ratios were statistically analyzed in order to verify xiv whether these variables corroborate the groups recovered in the molecular study. The combined analysis of the genes recovered the monophyly of the genus Gymnodactylus with high support. Two clades were evident both highly supported: a clade here called \"geckoides\" group (G. amarali, G. geckoides and a third lineage recognized here as a good species) and the \"darwinii\" one (G. darwinii, G. guttulatus, G. vanzolinii, and three other clades, also recognized as good species). All recognized species are described and diagnosed and a key for their identification presented. The variation of morphological characters is given for all species recognized as well as a detailed synonymy list based on an extensive survey of the literature and some types examined. Described as new without yet without a formal name are: (1) in \"geckoides\" group, a population of the Peruaçu valley region, northwest of Minas Gerais state, (2) in the group \"darwinii\", specimens from Grão Mogol municipality, south of the northern segment of the Espinhaço Range and two other clades from the Atlantic Rain Forest, one occurring between the region of the Rio Doce and Todos os Santos bay, and another to the north of this bay. Gymnodactylus vanzolinii is recovered in a basal position in the group \"darwinii\" either in combined or single analysis of some genes, but the monophyly of G. darwinii lato sensu is not recovered which led to the recognition of new species to the Atlantic Rain Forest. G. darwinii is therefore restricted to southeastern Brazil, occurring from northern São Paulo state to the Rio Doce region. Based on the distribution and ecology of the species here recognized, hypotheses to explain the origin and differentiation of the genus and its main lineages are presented. (AU)