Integrative revision of the Blommersia wittei complex, with description of a new species of frog from western and north-western Madagascar.

Frogs of the Blommersia wittei complex are widespread in western and northern Madagascar, and are one of two clades of the family Mantellidae that have colonized the Comoran island of Mayotte. Based on a comprehensive set of DNA sequences of the mitochondrial 16S rRNA gene and the nuclear-encoded RAG1 and SACS genes, integrated with morphological and bioacoustic data, we here analyze the genetic differentiation of populations of this complex across Madagascar. We confirm that a candidate species named B. sp. Ca5 in previous studies represents a genetically well-defined evolutionary lineage distributed over much of western Madagascar, which we describe herein as Blommeria bara sp. nov. based on its molecular and bioacoustic differentiation. Blommersia wittei occurs across northern Madagascar but its type locality Ambanja, at the lower Sambirano river, is very close to the range of another, newly discovered microendemic lineage that was only found at two sites along the upper Sambirano river (here named as candidate species B. sp. Ca12). The B. wittei complex thus provides an example of a clade of closely related Malagasy frogs that contains species widespread over hundreds of kilometers, as well as extreme microendemics. For a full resolution of this species complex, more data need to be collected on the geographical contact among these two lineages, on the morphology and bioacoustics of B. sp. Ca12, and on the north-eastern populations of B. wittei at Sambava, which are weakly differentiated in mitochondrial genes but differ in bioacoustics and possibly in the extent of foot webbing.

Integrative revision of the Lygodactylus madagascariensis group reveals an unexpected diversity of little brown geckos in Madagascars rainforest.

The Lygodactylus madagascariensis species group, constituting the subgenus Domerguella, currently contains five valid species of inconspicuous dwarf geckos from Madagascars humid forests, but at least 18 deep genetic lineages have been revealed by recent molecular studies. Given the high morphological similarity of these lineages, taxonomic resolution of this astonishing diversity requires efforts to correctly delimit species, as well as assigning the available nomina to the species-level lineages identified. We here combine DNA sequences of one mitochondrial and two nuclear-encoded gene fragments with morphometric measurements and scale counts, and report evidence for a species status of most of the previously identified lineages. In particular, we rely on sympatric and often even syntopic occurrence of several of these lineages without evidence for genetic admixture, and consistent with subtle morphological differences. Furthermore, the very high divergences of 7.423.8% pairwise distances in the relatively conserved mitochondrial 16S rRNA gene, combined with a lack of haplotype sharing in the nuclear-encoded genes and differences in scale counts convinced us that most of the other, allopatrically distributed lineages also represent distinct species. We elevate L. madagascariensis petteri to species level and formally name eight new species: L. salvi sp. nov., a species from the Sambirano region in northern Madagascar, previously called L. sp. 8; L. tantsaha sp. nov. (L. sp. 10), a species occurring sympatrically with L. madagascariensis and L. petteri on Montagne dAmbre in far northern Madagascar; L. roellae sp. nov. (L. sp. 17), a species characterized by a striped coloration in all known specimens, from northern Madagascar; L. winki sp. nov. (L. sp. 18), an unstriped species from northern Madagascar but belonging to a subclade mostly distributed in the eastern rainforests of the island; L. ulli sp. nov. (L. sp. 21), a species from the same subclade as L. winki but known only from the Marojejy Massif in the North East; L. fritzi sp. nov. (L. sp. 11), a further species of this subclade from coastal lowlands in the Northern Central East; L. hodikazo sp. nov. (L. sp. 23) known from a single specimen collected at the Tsingy de Bemaraha and therefore the only Domerguella species known from the West region of Madagascar; and L. hapei sp. nov. (L. sp. 26), an enigmatic species from the Sambirano region characterized by a striped pattern on the throat that is otherwise unknown in the subgenus. Three additional deep mitochondrial lineages of Domerguella were identified in our analysis, but could not be further analyzed due to the lack or scarcity of voucher specimens. More field work and collection of voucher specimens is needed to understand their status. Furthermore, the taxonomy of the Domerguella subclade occurring in eastern Madagascar, with three described species (L. guibei, L. miops, L. fritzi), two synonyms (L. septemtuberculatus, Microscalabotes spinulifer) and at least two further deep genetic lineages co-occurring in a relatively small area, requires further revisionary work, possibly aided by target-enrichment sequencing of the respective name-bearing types.

A comprehensive phylogeny of dwarf geckos of the genus Lygodactylus, with insights into their systematics and morphological variation.

The 71 currently known species of dwarf geckos of the genus Lygodactylus are a clade of biogeographic interest due to their occurrence in continental Africa, Madagascar, and South America. Furthermore, because many species are morphologically cryptic, our knowledge of species-level diversity within this genus is incomplete, as indicated by numerous unnamed genetic lineages revealed in previous molecular studies. Here we provide an extensive multigene phylogeny covering 56 of the named Lygodactylus species, four named subspecies, and 34 candidate species of which 19 are newly identified in this study. Phylogenetic analyses, based on ∼10.1 kbp concatenated sequences of eight nuclear-encoded and five mitochondrial gene fragments, confirm the monophyly of 14 Lygodactylus species groups, arranged in four major clades. We recover two clades splitting from basal nodes, one comprising exclusively Malagasy species groups, and the other containing three clades. In the latter, there is a clade with only Madagascar species, which is followed by a clade containing three African and one South American species groups, and its sister clade containing six African and two Malagasy species groups. Relationships among species groups within these latter clades remain weakly supported. We reconstruct a Lygodactylus timetree based on a novel fossil-dated phylotranscriptomic tree of squamates, in which we included data from two newly sequenced Lygodactylus transcriptomes. We estimate the crown diversification of Lygodactylus started at 46 mya, and the dispersal of Lygodactylus among the main landmasses in the Oligocene and Miocene, 35-22 mya, but emphasize the wide confidence intervals of these estimates. The phylogeny suggests an initial out-of-Madagascar dispersal as most parsimonious, but accounting for poorly resolved nodes, an out-of-Africa scenario may only require one extra dispersal step. More accurate inferences into the biogeographic history of these geckos will likely require broader sampling of related genera and phylogenomic approaches to provide better topological support. A survey of morphological characters revealed that most of the major clades and species groups within Lygodactylus cannot be unambiguously characterized by external morphology alone, neither by unique character states nor by a diagnostic combination of character states. Thus, any future taxonomic work will likely benefit from integrative, phylogenomic approaches.