Molecular phylogeny of Malagasy reed frogs, Heterixalus, and the relative performance of bioacoustics and color-patterns for resolving their systematics

Abstract

The members of the genus Heterixalus constitute one of the endemic frog radiations in Madagascar. Here we present a complete spe cies level phylogeny based on DNA sequences (4876 base pairs) of three nuclear and four mitochondrial markers to clarify the phylo genetic relationships among and within all known species of this genus, as well as the phylogenetic position of the monospecific Seychellean Tachycnemis seychellensis. Although the performance to resolve supported clades of Heterixalus species differed among the investigated gene fragments when analyzed separately, we could identify five well supported species groups within Heterixalus in the combined analysis of all gene fragments. Our data strongly support a Heterixalus Tachycnemis clade, and indicate the probable monophyly of Heterixalus placed sister to Tachycnemis. However, the diversification of these lineages may have happened in a short interval of time, leading to an unstable placement of Tachycnemis in the single gene fragment phylogenies. Referring to the hitherto exist ing classification of Heterixalus, which is predominantly based on chromatic and bioacoustic characters, we examined the relative per formance of these data sets relative to our molecular phylogeny. A Bayesian tree reconstructed with a bioacoustic data set yielded a higher resemblance to the molecular phylogeny than a tree constructed using a chromatic data set, which supports the importance of bioacoustic characters for systematic analyses of these anurans.

DNA barcoding Madagascar’s amphibian fauna

“…COI sequences of Malagasy amphibians have been previously obtained for the majority of Heterixalus species (Wollenberg et al, 2007) and for a nearly complete set of species of the family Mantellidae (Wollenberg et al, 2011). These were herein complemented by previously unpublished sequences of Malagasy microhylids obtained by Wollenberg et al (2008) in the context of a comprehensive phylogenetic study which eventually did not include this marker, and with newly determined sequences targeted to fill sampling gaps and to assess intraspecific variation in a representative set of species.…”

Evidence for an intrinsic factor promoting landscape genetic divergence in Madagascan leaf-litter frogs

“…For example, in African cichlid fishes, if optimal values for both extrinsic and intrinsic factors are in concordance (e.g., solar radiation and lake depth as extrinsic and sexual dichromatism as intrinsic), the likelihood of lineage diversification can be partially predicted (Wagner et al, 2012). The endemic Malagasy frog radiations have been extensively studied for their phylogenetic relationships (e.g., Wollenberg et al, 2007, 2008, 2011; Vieites et al, 2009) and biogeography, while less is known about their ecology (except for general ecological modes like habitat and breeding biology, Glaw and Vences, 2007). These frogs are sharing the island with other endemic radiations (Lemurs, Tenrecs, Vanga birds), resulting in patterns of diversification being shared among radiations and Madagascar thus constituting a good model region to infer the processes causing species diversity, species richness and endemism (Wollenberg et al, 2008; Vences et al, 2009).…”

Multi-gene phylogeny of Madagascar’s plated lizards, Zonosaurus and Tracheloptychus (Squamata: Gerrhosauridae)

“…Among the terrestrial vertebrates of the island, there are taxa whose closest evolutionary relationships are to Asian and South American species (Noonan and Chippindale, 2006;Warren et al, 2010;Samonds et al, 2012), but the majority of colonizations probably originated from ancestors rafting over the Mozambique Channel from mainland Africa (Yoder and Nowak, 2006). Such out-of-Africa rafting is particularly obvious in cases where the Malagasy clades are deeply nested within exclusively African groups, e.g., in frogs of the family Hyperoliidae Wollenberg et al, 2007), in lamprophiid snakes (Nagy et al, 2003), or in plated lizards of the family Gerrhosauridae (Crottini et al, 2012b).…”