Mohan, A. V., P.-S. Gehring, M. D. Scherz, F. Glaw, F. M. Ratsoavina & M. Vences

Comparative phylogeography and patterns of deep genetic differentiation of two gecko species, Paroedura gracilis and Phelsuma guttata, across north-eastern Madagascar. pp. 211-220 plus Supplementary data (PDF) and Supplementary Table S2 (Excel file).

Abstract. Phelsuma guttata and Paroedura gracilis are two species of geckos endemic to lowland and mid-elevation rainforests of the northern half of Madagascar’s rainforest band. To test for concordant phylogeographic patterns in the two species and to assess intraspecific phylogeny and genetic diversity, we sequenced DNA from two mitochondrial genes (16S and ND4) and three nuclear genes (CMOS, PDC, RAG1). The mtDNA trees of both species suggest a strong phylogeographic split between phylogroups from the North East and Northern Central East biogeographic regions of Madagascar. However, this pattern is not mirrored in the nuclear gene dataset, where common alleles can be found across the two biogeographic regions. Private alleles characterize some of the northernmost and southernmost populations, especially the Montagne d’Ambre population of P. gracilis. In this species the two main mitochondrial clades agree with two distinct dorsal colour pattern phenotypes – striped versus cross-banded – separated at the junction of North East and Northern Central East. As no obvious geographic barrier to gene flow is apparent, the observed concordant phylogeographic pattern indicates that the border between these two regions might represent an area of secondary contact after divergence in refugia. Both nuclear and mitochondrial DNA reveal a higher genetic divergence among lineages of P. gracilis as compared to Ph. guttata, calling for a more detailed taxonomic assessment of the former species.

Key words. Squamata, Gekkonidae, comparative phylogeography, genetic diversity, Madagascar.