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Based on sequences of three mitochondrial and two nuclear-encoded genes, we examine genetic variation in the leaf tailed geckos Uroplatus sameiti and U. sikorae, and morphological and chromatic characteristics of the genetic clusters identified. The mitochondrial phylogeny reveals a puzzling diversity of 16 deep lineages (4 in U. sameiti and 12 in U. sikorae) differing by 2.9–9.9% uncorrected pairwise distance in a fragment of the 16S rRNA gene. Populations from Analalava in the North and Zahamena in the Northern Central East form two mitochondrial lineages clustering with U. sameiti but being deeply divergent (>8% 16S distance); however, no information on their morphology is available. In U. sikorae, the mitochondrial lineages identified form several major geographic clades, two of which (from the northernmost and southernmost populations, respectively) received substantial support in the phylogenetic analysis. No instance of sympatry of two or more mitochondrial lineages was observed, precluding an unambiguous assessment of species status under the biological species criterion without experimental approaches or detailed hybrid zone analyses. In the fragment of the nuclear encoded gene SACS we observed haplotype sharing between species and mitochondrial lineages, while in the fragment of KIAA1239 no haplotype sharing was detected although neither species nor mitochondrial lineages formed coherent phylogroups in the respective network. A screening of colour patterns from live photos, partly of the genotyped individuals, confirmed a large variation within species and populations, with a possible sexual dichromatism where a longitudinally striped phenotype is restricted to males. All individuals from populations of the U. sikorae clade from the Southern Central East and South East had an unpigmented oral mucosa just like U. sameiti, while all other U. sikorae populations are characterized by a black oral mucosa pigmentation. The extremely strong phylogeographic structure in the U. sikorae complex without obvious species-level divergences is unprecedented for large-sized squamates in Madagascar and calls for further taxonomic scrutiny using phylogenomic approaches; and it exemplifies how the loss of any major block of the remaining rainforests in Madagascar will inevitably lead to a substantial loss of genetic diversity – even if often intraspecific – in rainforest-specialized species. [ABSTRACT FROM AUTHOR]

Biofluorescence is widespread in the natural world, but only recently discovered in terrestrial vertebrates. Here, we report on the discovery of iridophore-based, neon-green flourescence in the gecko Pachydactylus rangei, localised to the skin around the eyes and along the flanks. The maximum emission of the fluorescence is at a wavelength of 516 nm in the green spectrum (excitation maximum 465 nm, blue) with another, smaller peak at 430 nm. The fluorescent regions of the skin show large numbers of iridophores, which are lacking in the non-fluorescent parts. Two types of iridophores are recognized, fluorescent iridophores and basal, non-fluorescent iridophores, the latter of which might function as a mirror, amplifying the omnidirectional fluorescence. The strong intensity of the fluorescence (quantum yield of 12.5%) indicates this to be a highly effective mechanism, unique among tetrapods. Although the fluorescence is associated with iridophores, the spectra of emission and excitation as well as the small Stokes shifts argue against guanine crystals as its source, but rather a rigid pair of fluorophores. Further studies are necessary to identify their morphology and chemical structures. We hypothesise that this nocturnal gecko uses the neon-green fluorescence, excited by moonlight, for intraspecific signalling in its open desert habitat. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

We describe a large new species of leaf-tailed gecko endemic to northern Madagascar. Uroplatus garamaso sp. n. is the sister species of U. henkeli but differs by a genetic divergence > 8% in the mitochondrial 16S rRNA gene, by the absence of haplotype sharing in four nuclear-encoded genes analyzed, a smaller body size, slightly narrower tail, a more pronounced yellowish/reddish iris colour in most individuals, and lack of black pigmentation on the tip of the tongue. The new species also appears to consistently differ from U. henkeli in genital morphology, with the apex of the hemipenis ending in two terminal elements consisting of 4-5 rotulae and longitudinal rows of calyces (versus an apex with irregularly distributed calyces and ending in two symmetrical structures consisting of two broader serrated fleshy elements in U. henkeli). We genetically confirm the occurrence of U. henkeli over a rather wide area, ranging from Tsingy de Bemaraha in the West to Nosy Be in the Sambirano region of northern Madagascar. Both, U. henkeli and the new species contain several deep mitochondrial lineages that are considered as conspecific due to extensive haplotype sharing and lack of obvious morphological differences among them. [ABSTRACT FROM AUTHOR]

We describe the new gecko species Paroedura neglecta sp. n. from the Tsingy de Bemaraha National Park in western Madagascar, belonging to the P. bastardi/tanjaka clade. The species in this clade are characterized by three light dorsal crossbands on the dorsum of juveniles and subadults whereas all other Paroedura species have four such bands. The new species differs from all species in the P. bastardi complex in having the nostril in contact with the rostral scale. It is most similar to the sympatric P. tanjaka, from which it differs by the presence of prominent dorsal tubercles arranged in regular longitudinal rows (versus rather irregular rows of dorsal tubercles), smaller size, details of the dorsal colour pattern and strong genetic divergence. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multigene phylogeny of 56 Lygodactylus species reveals four well supported clades. • TIME calibrated analysis indicates multiple dispersal events between Madagascar and Continental Africa. • Morphological characters fail to reflect molecular phylogenetic results. • 15 New potential candidate sub-/species unveiled by this study double the number of undescribed Lygodactylus species. 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. [ABSTRACT FROM AUTHOR]