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Mites of the genus Geckobia (Acariformes: Pterygosomatidae) are permanent and highly specialised ectoparasites of geckos (Gekkota). We conducted a local study on Geckobia mites associated with the geckos of the family Gekkonidae found mainly in the territory of the Indian Institute of Science's campus (Bangalore, India). In total, we examined 208 lizards belonging to two genera: Hemidactylus and Cnemaspis. We assessed the prevalence of the mites and identified the preferred site for their infestation. We extended the standard morphological identification of the mite species by using DNA barcode markers, partial sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene and nuclear ribosomal gene sequences: 18S rRNA and hypervariable region D2 of nuclear 28S rRNA. We checked the suitability of COI and nuclear (D2 of 28S rRNA) markers for species delimitations and identification purposes of the genus. The distance- and phylogeny-based approaches were applied: (i) to test the presence of a barcoding gap, we used the automated barcoding gap discovery tool (ABGD) and investigated intra- and interspecific genetic distances, and (ii) to reconstruct evolutionary relationships within the species, we performed maximum likelihood (ML) and Bayesian inference with Markov-Chain Monte Carlo (BI) analyses. As a result, we described five new species—Geckobia gigantea sp. n., G. treutleri sp. n., G. unica sp. n. and G. brevicephala sp. n.—from four Hemidactylus species: H. giganteus, H. treutleri, H. parvimaculatus and H. frenatus, respectively, and G. mysoriensis sp. n. from Cnemaspis mysoriensis. Additionally, we found three already described species: Geckobia indica Hirst, 1917 on H. treutleri (new host), Geckobia bataviensis Vitzhum, 1926 on H. parvimaculatus (new host) and H. frenatus (new locality) and Geckobia phillipinensis Lawrence, 1953 on H. frenatus (new locality). The diagnoses of G. indica and G. phillipinensis were improved and supplemented by descriptions of the males and juveniles. Both topologies of the BI and ML phylogenetic trees, as well as genetic distances, supported the species boundaries in the mite population shown by the morphological data. Hemidactylus frenatus was the most infected gecko species (61% prevalence), with the highest number of mite species (three spp.). The scale-mite richness was higher than expected; therefore, further research is required to evaluate the true diversity of Geckobia mites. [ABSTRACT FROM AUTHOR]

Pimeliaphilus hemidactylisp. nov., a new species of the mite genus Pimeliaphilus Trägårdh (Acariformes: Pterygosomatidae), is described from four host species of Hemidactylus: H. murrayi Gleadow (type host), H. frenatus Duméril & Bibron, H. parvimaculatus Deraniyagala and H. leschenaultii Duméril & Bibron (Sauria: Gekkonidae) from India. P. hemidactylisp. nov. is the most similar to P. sharifiAbdussalam, 1941 and P. insignis (Berlese, 1892); this species can be distinguished from P. sharifi by the presence of 11 dorsal setae on the idiosoma, the absence of leg setae v"GII, v"TrIII and the presence of v'TrIV, and from P. sharifi by the presence of 11 dorsal setae on idiosoma, 1 pair of genital setae and the absence of coxal setae 4c. The standard morphological description of the new species is supplemented with sequencing data for cytochrome c oxidase subunit I (COI) and nuclear ribosomal genes: 18S rDNA and hypervariable region D2 of nuclear 28S rRNA. The present study also addresses specialisation amongst Pimeliaphilus hemidactylisp. nov. using two measures of host specificity: (1) the number of host species used by the mites species at the study area; and (2) a measure that considers the taxonomic distinctness of the hosts used by the mite, weighted for its prevalence in the different hosts. The results of this study indicate that this species is highly host specific (a stenoxenous species) and that, in the presence of coexisting gecko species, it prefers Murray's House gecko (H. murrayi) as a host (prevalence of 41%). A historical review of the genus is presented and a key to the genus is constructed. [ABSTRACT FROM AUTHOR]

Factors shaping biotic assembly of an island compared with the mainland are of considerable interest in biogeography, and the island of Sri Lanka and mainland India provide an interesting setting in which to study this process. We tested two contrasting hypotheses, faunal exchange vs. in situ diversification, to explain how the biota of Sri Lanka might have assembled. We studied the radiation of Hemidactylus geckos, endemic to India and Sri Lanka, to understand the biogeographical processes underlying the faunal assembly of Sri Lanka. We performed molecular phylogenetic analysis, divergence data estimation and ancestral area reconstruction. Diversification in this radiation began ~34.5 Mya in India, followed by seven independent dispersal events from India to Sri Lanka. Two dispersal events occurred in the Early to Middle Miocene, leading to two endemic Sri Lankan species. Marine transgression events separating the two landmasses are likely to have led to vicariant speciation in these cases. The other five dispersal events led to range expansion in species largely restricted to open semi-arid habitats and were likely to be more recent. These results indicate that the biotic exchange model better explains the assembly of Sri Lankan Hemidactylus geckos. [ABSTRACT FROM AUTHOR]

We sampled Palaearctic naked-toed geckos from across their range in India and used two mitochondrial and two nuclear genes to reconstruct relationships within a global phylogeny. Published sequences of Peninsular Indian Hemidactylus allow us to contrast these two groups in dating analyses - providing insights into the history of the Indian dry zone. Palaearctic naked-toed geckos first moved onto the Indian Plate in the Oligocene, with higher-level diversification probably linked to collision of the Indian and Eurasian plates, and subsequent dispersal into- India and diversification with increasing Miocene aridity. An independent gekkonid radiation with species in the dry zone, Hemidactylus diversified during the same period in Peninsular India. Our results demonstrate that dry zone taxa across India may date back to at least the Miocene, with a potential historical climatic barrier between the Indus and Peninsular Indian Divisions. ' Cyrtopodion' aravallense is revealed to be a complex with seven genetically and environmentally divergent lineages that began diversifying in the late Miocene, congruent with increased aridity in north-western India. This discovery of cryptic diversity in the Indian dry zone represents the first terrestrial vertebrate radiation from north-western central India and highlights how little we understand of the regions' biodiversity, emphasizing the need for systematic geographic sampling and multiline evidence to reveal true patterns of diversity. The ancestor of 'Cyrtopodion' aravallense came into the nascent Indian dry zone in the Miocene and has since diversified, potentially in the absence of any sympatric scansorial rupicolous geckos. Cyrtopodion scabrum represents a unique case of commensalism and shows phylogeographic structure in its presumed native range. The taxonomic implications of our study include a number of undescribed species, recognition of ' Cyrtopodion' as a distinct lineage and the non-monophyly of Altiphylax. [ABSTRACT FROM AUTHOR]

• Molecular phylogeny and species delimitation uncover multiple new and distinct lineages. • Lineage accumulation shows an early increase in diversification rates. • Dry habitat state at the basal node concurrent with Eocene–Oligocene cooling. • Presence of arid ecosystem inferred during Eocene–Oligocene period in Peninsular India. The Eocene–Oligocene cooling marks a global shift towards a cooler and drier climate, concurrent with significant turnover in biota globally. In Peninsular India, palynological investigations suggest a shift from wet rainforest vegetation to dry and seasonal species during this period. However, the grassland and open habitats that dominate this region at present expanded relatively recently due to Late Miocene intensification of monsoon seasonality. We test the possible role of these climatic shifts in generating the dry habitat diversity of an endemic radiation of Hemidactylus geckos distributed in both wet and dry habitats, by investigating whether (a) the beginning of the diversification of dry habitat lineages overlap with the Eocene–Oligocene cooling or late Miocene aridification and (b) accompanied by an increase in diversification. Molecular data (two nuclear and two mitochondrial gene fragments) were generated for samples collected across Peninsular India, and along with previously published data, a time-calibrated phylogeny was reconstructed. Ancestral state reconstruction of dry and wet habitat states was carried out on the time-calibrated phylogeny and γ-statistics along with a test for diversity-dependent diversification utilized to examine the trend in lineage accumulation. Results show the ancestral node of this radiation to have a dry habitat state, which began diversifying between 39 and 32 million years ago, concurrent with the Eocene–Oligocene cooling. Furthermore, lineage diversification fit a diversity-dependent model of diversification and the γ-statistics revealed an early increase in diversification followed by a slowdown later. The deep divergences of dry habitat lineages concurrent with the Eocene–Oligocene cooling suggest that this could have served as an ecological opportunity facilitating an early increase in lineage diversification of Hemidactylus in this region. These results suggest an ancient origin and long persistence of arid ecosystems in Peninsular India. [ABSTRACT FROM AUTHOR]