Generalizing Bayesian phylogenetics to infer shared evolutionary events.

Many processes of biological diversification can simultaneously affect multiple evolutionary lineages. Examples include multiple members of a gene family diverging when a region of a chromosome is duplicated, multiple viral strains diverging at a "super-spreading" event, and a geological event fragmenting whole communities of species. It is difficult to test for patterns of shared divergences predicted by such processes because all phylogenetic methods assume that lineages diverge independently. We introduce a Bayesian phylogenetic approach to relax the assumption of independent, bifurcating divergences by expanding the space of topologies to include trees with shared and multifurcating divergences. This allows us to jointly infer phylogenetic relationships, divergence times, and patterns of divergences predicted by processes of diversification that affect multiple evolutionary lineages simultaneously or lead to more than two descendant lineages. Using simulations, we find that the method accurately infers shared and multifurcating divergence events when they occur and performs as well as current phylogenetic methods when divergences are independent and bifurcating. We apply our approach to genomic data from two genera of geckos from across the Philippines to test if past changes to the islands' landscape caused bursts of speciation. Unlike previous analyses restricted to only pairs of gecko populations, we find evidence for patterns of shared divergences. By generalizing the space of phylogenetic trees in a way that is independent from the likelihood model, our approach opens many avenues for future research into processes of diversification across the life sciences.

Cryptic diversity and phylogeographic patterns of Mediodactylus species in the Eastern Mediterranean region.

Cryptic diversity poses a great obstacle in our attempts to assess the current biodiversity crisis and may hamper conservation efforts. The gekkonid genus Mediodactylus, a well-known case of hidden species and genetic diversity, has been taxonomically reclassified several times during the last decade. Focusing on the Mediterranean populations, a recent study within the M. kotschyi species complex using classic mtDNA/nuDNA markers suggested the existence of five distinct species, some being endemic and some possibly threatened, yet their relationships have not been fully resolved. Here, we generated genome-wide SNPs (using ddRADseq) and applied molecular species delimitation approaches and population genomic analyses to further disentangle these relationships. Τhe most extensive nuclear dataset, so far, encompassing 2,360 loci and âˆ¼ 699,000 bp from across the genome of Mediodactylus gecko, enabled us to resolve previously obscure phylogenetic relationships among the five, recently elevated, Mediodactylus species and to support the hypothesis that the taxon includes several new, undescribed species. Population genomic analyses within each of the proposed species showed strong genetic structure and high levels of genetic differentiation among populations.

New host and locality records of helminths' infection of seven lizards from Morocco.

Morocco has a great diversity of reptiles; more than 26% of the herpetofauna species are considered to be endemic. Nevertheless, there is little information available on helminth parasites of Moroccan lizards. The purpose of this article is to establish a helminth list using non-invasive methods for natural populations of seven lizard species: Acanthodactylus maculatus, Chalcides mionecton, Chalcides montanus, Chalcides polylepis, Quedenfeldtia moerens, Quedenfeldtia trachyblepharus, and Tarentola mauritanica. For each species, prevalence and intensity of infection were given as well as their relationship to some determinant parameters (sex, age class, size, altitude, and seasons). Four species of nematodes, Parapharyngodon micipsae, Pharyngodon mamillatus, Spauligodon auziensis, Thelandros alatus, and unassigned Spauligodon were found. Mean helminth intensity for the seven lizard species was 7.3 ± 16.2 SD (range = 1-92 in infected lizards), with total infection prevalence of 5.6%. Mixed infections were observed in Chalcides montanus and Chalcides polylepis co-infected by Pharyngodon mamillatus and Spauligodon sp. Furthermore, the intensity of infection by nematodes were significantly different among the seven studied species. The nematode infection in Chalcides mionecton were related to sex, host size, and altitude; in Chalcides polylepis to the host age; in Quedenfeldtia trachyblepharus to elevation, age, and host size; and in Tarentola Mauritanica to age, body size, seasons, and altitude. In conclusion, our study provides data about nine new host and locality records and the effect of some determinant factors on host parasitism.

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.

The same but different: setal arrays of anoles and geckos indicate alternative approaches to achieving similar adhesive effectiveness.

The functional morphology of squamate fibrillar adhesive systems has been extensively investigated and has indirectly and directly influenced the design of synthetic counterparts. Not surprisingly, the structure and geometry of exemplar fibrils (setae) have been the subject of the bulk of the attention in such research, although variation in setal morphology along the length of subdigital adhesive pads has been implicated to be important in the effective functioning of these systems. Adhesive setal field configuration has been described for several geckos, but that of the convergent Anolis lizards, comprised of morphologically simpler fibrils, remains largely unexplored. Here, we examine setal morphology along the proximodistal axis of the digits of Anolis equestris and compare our findings to those for a model gecko, Gekko gecko. Consistent with previous work, we found that the setae of A. equestris are generally thinner, shorter, and present at higher densities than those of G. gecko and terminate in a single spatulate tip. Contrastingly, the setae of G. gecko are hierarchically branched in structure and carry hundreds of spatulate tips. Although the splitting of contacts into multiple smaller tips is predicted to increase the adhesive performance of a fiber compared to an unbranched one, we posited that the adhesive performance of G. gecko and A. equestris would be relatively similar when the configuration of the setal fields of each was accounted for. We found that, as in geckos, setal morphology of A. equestris follows a predictable pattern along the proximodistal axis of the pad, although there are several critical differences in the configuration of the setal fields of these two groups. Most notably, the pattern of variation in setal length of A. equestris is effectively opposite to that exhibited by G. gecko. This difference in clinal variation mirrors the difference in the direction in which the setal fields of anoles and geckos are peeled from the substrate, consistent with the hypothesis that biomechanical factors are the chief determinants of these patterns of variation. Future empirical work, however, is needed to validate this. Our findings set the stage for future comparative studies investigating the functional morphology of these convergent adhesive apparatuses. Such investigations will lead to an enhanced understanding of the interactions between form, function, and environment of fibril-based biological adhesive systems.

Determinants of prevalence and co-infestation by ecto- and endoparasites in the Atlas day gecko, Quedenfeldtia trachyblepharus, an endemic species of Morocco.

The present work was undertaken to investigate the occurrence of ectoparasites (mites and ticks) and endoparasites (haemogregarines and helminths) in the Atlas day gecko, Quedenfeldtia trachyblepharus (Boettger, 1874), a high-altitude Moroccan endemic lizard. The study examinated also the effect of some host parameters (age, sex, size, body condition), in addition to the season and altitude on the prevalence and intensity of parasite infestations. The study was conducted in three localities from May to September 2019. The results indicated that 35% of juvenile geckos were found to be parasited by one type of parasite. Contrarily, up to three types of parasites were detected in the adults. The prevalence of mite infestations was 48.02%, with a mean intensity of 11.80 ± 15.69. The patterns of mite infestations was found to be mainly related to the altitude, while the prevalence and intensity of infestations were linked to the host size, and to the sex and season, respectively. Larvae and nymphs of Ixodes ricinus (Linnaeus, 1758) were the only life stages infesting geckos, with a prevalence and mean intensity of infestations of 4.41% and 2.2 ± 1.48, respectively. The tick infestations observed were mainly related to the season. The prevalence and intensity of haemogregarine infections were, respectively, 7.92% and 0.24 ± 0.15. The altitude was found to be the only factor associated with this infection. This study also revealed the presence of one helminth genus, Spauligodon sp., with a prevalence and mean intensity of 12.33% and 1.46 ± 0.88, respectively. Spauligodon infestations was significantly associated with age, host size and altitude. This finding represents the first citation of this parasite in Quedenfeldtia genus. Our study indicated that there was no significant relationship between parasite load and geckos body condition, which suggested a stable interaction between the gecko and its parasites. However, it showed a difference of infection between the localities, which could be in relation with habitat conditions.

Distinct patterns of pigment development underlie convergent hyperpigmentation between nocturnal and diurnal geckos (Squamata: Gekkota).

BACKGROUND: Evolutionary transitions in temporal niche necessitates specialized morphology, physiology, and behaviors. Diurnal, heliothermic squamates (lizards and snakes) that bask require protection from ultraviolet radiation (UV) that can damage internal organs such as the brain, viscera, and gonads. Many smaller squamates have accomplished this protection by hyperpigmentation of the peritoneum and subcutaneous dorsum. Typically, nocturnal species do not require these protections from ultraviolet light. However, some nocturnal species that exhibit extreme crypsis may be exposed to sunlight and UV and require some means of mediating that damage. One such species is Gekko (Ptychozoon) kuhli, a nocturnal, arboreal gecko that uses extreme crypsis to blend in with tree bark. Hiding motionless on tree trunks leaves geckos exposed to sunlight during the day. Thus, we predict that G. kuhli will have independently evolved a hyperpigmented phenotype. To investigate this hypothesized association between temporal niche, behavior, and morphology, we characterized adult subcutaneous pigment for eight gecko species and embryonic pigment accumulation for a subset of four of these species, exhibiting diverse temporal niche and thermoregulatory behaviors. We predicted that nocturnal/potentially-heliothermic G. kuhli would exhibit hyperpigmentation of internal structures like that of diurnal/heliothermic geckos. We further predicted that embryonic pigment accumulation of G. kuhli would resemble that of diurnal/heliothermic as opposed to nocturnal/thigmothermic geckos. RESULTS: We found that temporal niche and thermoregulatory behavior predicted the degree of subcutaneous pigment in the eight gecko species examined. We demonstrate that G. kuhli accumulates pigment extremely early in embryonic development, unlike a diurnal/heliothermic gecko species, despite having a similar adult phenotype. CONCLUSIONS: The evolution of hyperpigmentation in G. kuhli is likely an adaptation to limit damage from occasional daytime UV exposure caused by crypsis-associated basking behavior. Gekko kuhli achieves its hyperpigmented phenotype through a derived developmental pattern, not seen in any other lizard species investigated to date, suggesting novel temporal differences in the migration and/or differentiation of reptilian neural crest derivatives.

Home-field advantage: native gecko exhibits improved exertion capacity and locomotor ability in structurally complex environments relative to its invasive counterpart.

BACKGROUND: Invasive species are of substantial concern because they may threaten ecosystem stability and biodiversity worldwide. Not surprisingly, studies examining the drivers of biological invasion have increased in number over the past few decades in an effort to curtail invasive species success by way of informing management decisions. The common house gecko, Hemidactylus frenatus, has successfully invaded the Pacific islands where it appears to thrive in and dominate non-natural habitats offering high food availability (i.e., well-lit human dwellings) compared to native geckos. Previous work demonstrated that H. frenatus can outperform the native gecko, Lepidodactylus lugubris, in terms of maximal sprint speed on relatively simple planar surfaces (e.g., building walls). Lepidodactylus lugubris and other native geckos, however, may have superior locomotor performance in three-dimensional, structurally complex habitats. RESULTS: Here we compared the locomotor behaviour and exertion capacity of the native gecko, Gehyra oceanica, and the invasive gecko, Hemidactylus frenatus, on the island of Mo'orea, French Polynesia, on fabricated structures simulating structurally complex substrates. We found that the native gecko exhibits improved locomotor performance compared to the invasive gecko on structurally complex substrates. We also completed encounter surveys to document free-ranging habitat use and behaviour of these two species. We discovered that H. frenatus were more common in natural habitats than previously observed and used similar substrates as G. oceanica, although G. oceanica appeared to use substrates with greater perch heights (i.e., trees). CONCLUSIONS: Our findings revealed that locomotor performance in complex environments may contribute to the previously observed habitat segregation between native and invasive Pacific island geckos. Furthermore, our locomotor and habitat use data are consistent with the hypothesis that G. oceanica may be resistant to invasion of H. frenatus in natural environments. Our study calls for more detailed ecophysiological and ecomorphological studies of both native and invasive Pacific gecko species.

Multilocus phylogeny and coalescent species delimitation in Kotschy's gecko, Mediodactylus kotschyi: Hidden diversity and cryptic species.

Kotschy's Gecko, Mediodactylus kotschyi, is a small gecko native to southeastern Europe and the Levant. It displays great morphological variation with a large number of morphologically recognized subspecies. However, it has been suggested that it constitutes a species complex of several yet unrecognized species. In this study, we used multilocus sequence data (three mitochondrial and three nuclear gene fragments) to estimate the phylogenetic relationships of 174 specimens from 129 sampling localities, covering a substantial part of the distribution range of the species. Our results revealed high genetic diversity of M. kotschyi populations and contributed to our knowledge about the phylogenetic relationships and the estimation of the divergence times between them. Diversification within M. kotschyi began approximately 15 million years ago (Mya) in the Middle Miocene, whereas the diversification within most of the major clades have been occurred in the last 5 Mya. Species delimitation analysis suggests there exists five species within the complex, and we propose to tentatively recognize the following taxa as full species: M. kotschyi (mainland Balkans, most of Aegean islands, and Italy), M. orientalis (Levant, Cyprus, southern Anatolia, and south-eastern Aegean islands), M. danilewskii (Black Sea region and south-western Anatolia), M. bartoni (Crete), and M. oertzeni (southern Dodecanese Islands). This newly recognized diversity underlines the complex biogeographical history of the Eastern Mediterranean region.

Multilocus phylogeography reveals nested endemism in a gecko across the monsoonal tropics of Australia.

Multilocus phylogeography can uncover taxonomically unrecognized lineage diversity across complex biomes. The Australian monsoonal tropics include vast, ecologically intact savanna-woodland plains interspersed with ancient sandstone uplands. Although recognized in general for its high species richness and endemism, the biodiversity of the region remains underexplored due to its remoteness. This is despite a high rate of ongoing species discovery, especially in wetter regions and for rock-restricted taxa. To provide a baseline for ongoing comparative analyses, we tested for phylogeographic structure in an ecologically generalized and widespread taxon, the gecko Heteronotia binoei. We apply coalescent analyses to multilocus sequence data (mitochondrial DNA and eight nuclear DNA introns) from individuals sampled extensively and at fine scale across the region. The results demonstrate surprisingly deep and geographically nested lineage diversity. Several intra-specific clades previously shown to be endemic to the region were themselves found to contain multiple, short-range lineages. To infer landscapes with concentrations of unique phylogeographic diversity, we probabilistically estimate the ranges of lineages from point data and then, combining these estimates with the nDNA species tree, estimate phyloendemism across the region. Highest levels of phyloendemism occur in northern Top End, especially on islands, across the topographically complex Arnhem escarpment, and across the sandstone ranges of the western Gulf region. These results drive home that deep phylogeographic structure is prevalent in tropical low-dispersal taxa, even ones that are ubiquitous across geography and habitats.

Light level impacts locomotor biomechanics in a secondarily diurnal gecko, Rhoptropus afer.

Locomotion through complex habitats relies on the continuous feedback from a number of sensory systems, including vision. Animals face a visual trade-off between acuity and light sensitivity that depends on light levels, which will dramatically impact the ability to process information and move quickly through a habitat, making ambient illumination an incredibly important ecological factor. Despite this, there is a paucity of data examining ambient light in the context of locomotor dynamics. There have been several independent transitions from the nocturnal ancestor to a diurnal activity pattern among geckos. We examined how ambient light level impacted the locomotor performance and high-speed three-dimensional kinematics of a secondarily diurnal, and cursorial, gecko (Rhoptropus afer) from Namibia. This species is active under foggy and sunny conditions, indicating that a range of ambient light conditions is experienced naturally. Locomotor speed was lowest in the 'no-light' condition compared with all other light intensities, occurring via a combination of shorter stride length and lower stride frequency. Additionally, the centre of mass was significantly lower, and the geckos were more sprawled, in the no-light condition relative to all of the higher light intensities. Locomotor behaviour is clearly sub-optimal under lower light conditions, suggesting that ecological conditions, such as very dense fog, might preclude the ability to run quickly during predator-prey interactions. The impact of ambient light on fitness should be explored further, especially in those groups that exhibit multiple transitions between diel activity patterns.

A molecular phylogeny of Afromontane dwarf geckos (Lygodactylus) reveals a single radiation and increased species diversity in a South African montane center of endemism.

Afromontane habitats throughout eastern sub-Saharan Africa support remarkable levels of microendemism. However, despite being the subject of decades of research interest, biogeographical patterns of diversification throughout this disjunct montane system still remain largely unknown. We examined the evolutionary relationships of diurnal dwarf geckos (Lygodactylus) from several Afromontane regions throughout southeastern Africa, focusing primarily on two species groups (rex and bonsi groups). Using both mitochondrial and nuclear markers, we generate a molecular phylogeny containing all members of the rex and bonsi groups, to evaluate the monophyly of these groups along with previous biogeographic hypotheses suggesting independent southward invasions into the greater Drakensberg Afromontane center of endemism in northeastern South Africa by each group. Our results provide no support for these taxonomic and biogeographic hypotheses, and instead reveal geographically circumscribed patterns of diversification. One clade is restricted to the highlands of southern Malawi and northern Mozambique and the other to the greater Drakensberg region of northeastern South Africa and Swaziland. Interestingly, L. bernardi from the Nyanga Highlands of eastern Zimbabwe is nested within the primarily savanna-dwelling capensis group. We use Bayesian species delimitation methods to evaluate species limits within the greater Drakensberg clade, which support the elevation of the subspecies of L. ocellatus and L. nigropunctatus, thus bringing the total to eight species within a relatively confined geographic area. These results further highlight the greater Drakensberg Afromontane region as both an important center of endemism, as well as a center of diversification contributing to the accumulation of southern Africa's rich species diversity.

The first complete mitochondrial DNA of Tenuidactylus dadunensis (Squamata: Gekkonidae) and its phylogeny.

The complete mitochondrial DNA (mtDNA) of Tenuidactylus dadunensis (Squamata: Gekkonidae) was described by using next-generation sequencing. The total length of mtDNA was 16,893 bp, which contained 13 PCGs (COX1-3, ND1-6, ND4L, ATP6, ATP8, and CYTB), 22 transfer RNA(tRNA) genes, 2 ribosomal RNA (rRNA) genes, and a control region (D-loop). The Bayesian inference tree showed that T. dadunensis was included in Gekkonidae and was a sister taxon to Cyrtopodion scabrum. The complete mtDNA of T. dadunensis will be an important genetic resource to the studies of conservation and research of geckonids.

Cytogenetic Analysis of Satellitome of Madagascar Leaf-Tailed Geckos.

Satellite DNA (satDNA) consists of sequences of DNA that form tandem repetitions across the genome, and it is notorious for its diversity and fast evolutionary rate. Despite its importance, satDNA has been only sporadically studied in reptile lineages. Here, we sequenced genomic DNA and PCR-amplified microdissected W chromosomes on the Illumina platform in order to characterize the monomers of satDNA from the Henkel's leaf-tailed gecko U. henkeli and to compare their topology by in situ hybridization in the karyotypes of the closely related Günther's flat-tail gecko U. guentheri and gold dust day gecko P. laticauda. We identified seventeen different satDNAs; twelve of them seem to accumulate in centromeres, telomeres and/or the W chromosome. Notably, centromeric and telomeric regions seem to share similar types of satDNAs, and we found two that seem to accumulate at both edges of all chromosomes in all three species. We speculate that the long-term stability of all-acrocentric karyotypes in geckos might be explained from the presence of specific satDNAs at the centromeric regions that are strong meiotic drivers, a hypothesis that should be further tested.

The Fergana Valley Is an Isolate of Biodiversity: A Discussion of the Endemic Herpetofauna and Description of Two New Species of Alsophylax (Sauria: Gekkonidae) from Eastern Uzbekistan.

The high level of endemism in Fergana Valley has been well documented in numerous studies for various groups of animals and plants. In a relatively small area, there are 45 endemic plant species, five endemic insect species, and five endemic reptile species. In surveying this area for data on distribution, abundance, acoustics, and genetic samples for species of reptiles, we discovered two new species of gecko from the genus Alsophylax. Phylogenetic analyses of mitochondrial DNA sequences indicate the relatives of these new species are the even-fingered gecko, Alsophylax pipiens, and the southern even-fingered gecko, Alsophylax laevis, located hundreds of kilometers to the northwest and southwest of the Fergana Valley. The threats to these new endemic species are significant given the amount of continued agricultural development that involves new territories previously considered "unsuitable" for any species of significance that is leading to the further reduction in, fragmentation of, and degradation of the remaining natural ecosystems in the Fergana Valley. The conservation of these rare and locally endemic species depends directly on the readiness of the state to create areas with IUCN I and II protection. The many studies documenting levels of endemism, along with the data published in this study, are the basis for the justification for state-protected areas in the Fergana Valley.

A New Species of the Genus Gekko (Squamata: Sauria: Gekkonidae) from the Dabie Mountains, China.

This study describes a novel species of Gekko (Squamata: Gekkonidae) based on its distinct morphological features and molecular evidence, which was identified in the Dabie Mountains on the border of Anhui and Henan provinces of Central China. Gekko kaiyaisp. nov. could be distinguished from its congeners owing to its morphological characteristics, such as being a medium body sized gecko species (snout-vent length, 56.98-64.99 mm, n = 4, females; 50.03-61.56 mm, n = 11, males); nostrils scale in contact with rostral scale; tubercles on the dorsal and limb, while the upper forelimb is smooth with no tubercles; 22-33 interorbital scales between the anterior corners of the eyes; 157-209 ventral scales between mental and cloacal slit; 90-121 midbody scale rows; 30-43 ventral scale rows; 7-9 sub-digital lamellae on first fingers, 8-13 fourth fingers, 7-9 first toes, and 7-11 fourth toes; free of webbing in the fingers and toes; 9-12 pre-cloacal pores in males, which are absent in females; post-cloacal unilateral tubercles 1 (few 2); and a dorsum that is greyish white to dark brown, with 6-7 brown markings between the nape and sacrum. The phylogenetic tree based on the mitochondrial DNA sequences (16S, CYTB, and COI) indicated that Gekko kaiyaisp. nov. form an independent clade with strong support (100/1) and are a sister group to G. hokouensis. At the inter-species level, the genetic distances were all large, further confirming that an independent species had been identified. The discovery of this species implies that there are now 87 identified species in the genus Gekko, 22 of which can be found within China.

How many more species are out there? Current taxonomy substantially underestimates the diversity of bent-toed geckos (Gekkonidae, Cyrtodactylus) in Laos and Vietnam.

Cyrtodactylus is the most diverse genus of the family Gekkonidae and the world's third largest vertebrate genus. The number of species has increased more than fourfold over the last two decades. Indochina, especially Vietnam and Laos, has witnessed a surge in new species discoveries over the last three decades. The species number reported from Laos and Vietnam has remarkably increased from five in 1997 to 71 species in 2021. However, within the genus, several taxonomic issues have not yet been fully resolved. Based on recently collected samples from Laos and Vietnam, we conducted a comprehensive molecular review of Cyrtodactylus occurring in Laos and Vietnam. Our molecular analysis with support from morphological comparisons showed that C.thuongae is a junior synonym of C.dati and C.rufford is a junior synonym of C.lomyenensis. In total, 68 described species distributed in Laos and Vietnam are undisputed with strong support from both molecular and morphological evidence. On the other hand, the molecular analyses revealed that there are at least seven undescribed species in Vietnam and Laos, one in the C.angularis group, one in the C.chauquangensis, and five in the C.irregularis group. This number will likely increase significantly, as previous work suggested that the C.angularis and C.irregularis groups harbor three and six unnamed lineages, respectively. Based on survey gaps identified in our study, it is clear that additional new species will be discovered in poorly studied regions of central Vietnam and northern and southern Laos. As many species in the genus are facing high extinction risks, several undescribed populations might already be severely threatened by human activities in both countries. Therefore, urgent taxonomic research is needed before conservation assessments of newly discovered taxa can be undertaken to protect them from anthropogenic threats.

Morphological redescription and phylogenetic assessment of Spauligodon aspiculus (Oxyuroidea: Pharyngodonidae) infecting the white-spotted gecko, Tarentola annularis (Squamata: Gekkonidae).

Thirty white-spotted geckos, Tarentola annularis, from the South Sinai desert in Egypt, were examined for helminth parasites. Spauligodon aspiculus was observed to infect 19 geckos with 63.33% as a prevalence of parasitic infection. The present nematode species is separated from congeners by morphological and metrical characteristics such as lateral alae, aspinose filamentous tail, and no spicule, and three pairs of caudal papillae with posterior pair excluded from envelopment by the caudal alae in the male worms, and knobbed eggs, and postbulbar vulva in females. It compared morphometrically with other Spauligodon species described previously and showed few differences in measurements. Molecular characterization based on the partial 28S rRNA nuclear ribosomal gene sequence showed that there was a close identity, up to 72%, with other sequences retrieved from GenBank. Phylogenetic analysis showed that the parasite sequence in conjunction with existing data facilitates the investigation of the placement of this pharyngodonid species within Oxyuridae. The present species is deeply embedded in the genus Spauligodon with close relationships to previously described Spauligodon nicolauensis (gb| JN619349.1, and JF829243.1) as more related sister taxa. This study highlights the importance of combining genetic and morphological data with taxonomy in pharyngodonid species.

Digital hyperextension has no influence on the active self-drying of gecko adhesive subdigital pads.

The remarkable properties of the gecko adhesive system have been intensively studied. Although many gecko-inspired synthetic adhesives have been designed and fabricated, few manage to capture the multifunctionality of the natural system. Analogous to previously documented self-cleaning, recent work demonstrated that gecko toe pads dry when geckos take steps on dry substrates (i.e., self-drying). Whether digital hyperextension (DH), the distal to proximal peeling of gecko toe pads, is involved in the self-drying process, had not been determined. Here, the effect of DH on self-drying was isolated by preventing DH from occurring during normal walking locomotion of Gekko gecko after toe pads were wetted. Our initial analysis revealed low statistical power, so we increased our sample size to determine the robustness of our result. We found that neither DH nor the DH-substrate interaction had a significant effect on the maximum shear adhesive force after self-drying. These results suggest that DH is not necessary for self-drying to occur. Interestingly, however, we discovered that shear adhesion is higher on a surface tending hydrophobic compared to a hydrophilic surface, demonstrating that gecko adhesion is sensitive to substrate wettability during the subdigital pad drying process. Furthermore, we also observed frequent damage to the adhesive system during shear adhesion testing post-drying, indicating that water may compromise the structural integrity of the adhesive structures. Our results not only have behavioral and ecological implications for free-ranging geckos but also have the potential to influence the design and fabrication of gecko-inspired synthetic adhesives that can regain adhesion after fouling with water.

A new limestone-dwelling leaf-toed gecko (Gekkonidae: Dixonius) from coastal hills in Cha-am, peninsular Thailand.

We describe Dixonius pawangkhananti sp. nov. from coastal limestone hills in Cha-am District, Phetchaburi Province, peninsular Thailand. The new species differs from all currently recognized Dixonius by the following combination of morphological characters and pattern: maximal known snout-vent length of 42.6 mm; 16 longitudinal rows of dorsal tubercles; 30 to 32 paravertebral scales; 16 longitudinal rows of ventral scales across the abdomen; six precloacal pores in males, no pores in females; a marked canthal stripe; and a sexually dimorphic dorsal pattern consisting of bands (males) or blotches (females). This description brings the number of Dixonius species to ten, with four species endemic to Thailand.