Mitochondrial NADH Dehydrogenase Subunit Research Articles

Contrasting the role of historic factors in phylogeograpic patterns in the native Johnny darter (Etheostoma nigrum) and invasive round goby (Neogobius melanostomus) in lower michigan.

Round goby (Neogobius melanostomus) is an invasive fish present in all five Great Lakes and is becoming increasingly common in their tributaries. Johnny darter (Etheostoma nigrum) is a native species that often coexists with N. melanostomus. In this work, historic factors are addressed as a source of genomic variation in study populations of these species. To do this, patterns of variation in the mitochondrial gene NADH dehydrogenase subunit 2 (ND2) were characterized for both species throughout Lower Michigan. Populations of N. melanostomus and E. nigrum were sampled from 17 localities representing both eastern and western basins of Lower Michigan to test the hypothesis that populations differ between the eastern and western basins of the Great Lakes. Neogobius melanostomus populations were largely homogenous with no significant differences detected among populations or between the eastern and western basins. Additionally, N. melanostomus exhibited no evidence of overarching historical genetic structure, consistent with the recent invasion and rapid expansion of this species. Etheostoma nigrum exhibited significant differentiation among local populations; however, similarity among mtDNA haplotypes indicated that differences among populations are recent, suggesting that local forces are a more important factor in shaping patterns of variation than historical factors. Contrary to predictions, there were no significant differences detected between the eastern and western basins of the Great Lakes; however, construction of a neighbor-joining tree with F ST estimates revealed clustering of populations by basin with some anomalies. These anomalies may be the result of recent stream capture events facilitating gene flow between the two basins.

The seventh species of the newt genus Tylototriton in Thailand: a new species (Urodela, Salamandridae) from Tak Province, northwestern Thailand.

A new species of the crocodile newt genus Tylototriton from Doi Soi Malai located at Mae Tuen Wildlife Sanctuary, Tak Province, northwestern Thailand is described based on molecular and morphological evidence, and named as Tylototritonsoimalai sp. nov. The new species is the seventh recorded species of the genus Tylototriton reported in Thailand. It differs morphologically from its congeners by a combination of the following morphological characteristics: head longer than wide; snout blunt or truncate; sagittal ridge on head narrow, short and distinct; dorsolateral bony ridges on head pronounced and rough; parotoids distinct; vertebral ridge prominent, wide and not segmented; 14-16 distinct, rounded and isolated rib nodules but posterior nodules connected; tips of fore- and hind limbs overlapping when adpressed along the body. The body background color is black, while the color markings are orange. Molecular analysis indicated that Tylototritonsoimalai sp. nov. is a distinct lineage and sister to T.uyenoi with a 4.1% genetic sequence divergence based on the mitochondrial NADH dehydrogenase subunit 2 gene. The new species is currently restricted to the hill evergreen forests of Doi Soi Malai. The implementation of a strategic plan is recommended to protect both the species and its habitat from anthropogenic activities.

A new species of karst-dwelling bent-toed gecko of the Cyrtodactylusintermedius group (Squamata, Gekkonidae) from eastern Thailand and the phylogenetic placement of C.intermedius.

A new karst-dwelling bent-toed gecko of the Cyrtodactylusintermedius group is described from Khlong Hat District, Sa Kaeo Province, eastern Thailand, based on an integrative taxonomic analysis of genetic data and morphological characteristics. Phylogenetic analyses using the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene revealed that topotypes of C.intermedius were sister to a clade containing C.kulenensis from Cambodia, an unnamed lineage from Sakaerat Biosphere Reserve in Nakhon Ratchasima Province, Thailand, and the Khlong Hat lineage described here as Cyrtodactyluskhlonghatensis sp. nov. Multivariate analyses of morphometric and meristic characters showed that C.khlonghatensis sp. nov. is morphologically distinct from all other species in the group by having the combination of SVL 76.5-82.8 mm in adult males and 88.5 mm in an adult female; eight supralabial and nine infralabial scales; 30-32 paravertebral tubercles; 20 or 21 longitudinal rows of dorsal tubercles; 43 or 44 ventral scales; seven or eight expanded subdigital lamellae on the 4th toe; 12 unmodified subdigital lamellae on the 4th toe; 19 or 20 total subdigital lamellae on the 4th toe; 31 or 32 total number of enlarged femoral scales; enlarged femoral and precloacal scales continuous; 6-8 pore-bearing precloacal scales in males; three or four rows of enlarged post-precloacal scales; 1-3 postcloacal tubercles; proximal femoral scales less than one-half the size of distal femoral scales; absence of interdigital pocketing between digits of forefeet and hindfeet; and posterior border of the nuchal loop rounded. Uncorrected pairwise genetic divergences (p-distances) between the new species and other species of the intermedius group ranged from 4.73-22.55%. The discovery of this new species exclusively in isolated karst formations from the Thai-Cambodia border suggests that there may be further undiscovered Cyrtodactylus in unexplored karst landscapes along the border of eastern Thailand and western Cambodia.

Phylogenetic relationships and systematics of tapeworms of the family Davaineidae (Cestoda, Cyclophyllidea), with emphasis on species in rodents.

The present study aims at clarifying the poorly known phylogenetic relationships and systematics of cestodes of the family Davaineidae Braun, 1900 (Cyclophyllidea), primarily the genus Raillietina Fuhrmann, 1920 and of the subfamily Inermicapsiferinae (Anoplocephalidae) from mammals (mostly rodents, 31 new isolates) and birds (eight new isolates). Phylogenetic analyses are based on sequences of the large subunit ribosomal RNA gene (28S) and mitochondrial NADH dehydrogenase subunit 1 gene (nad1). The main phylogenetic pattern emerging from the present analysis is the presence of three independent lineages within the main clade of the subfamily Davaineinae, one of which is almost entirely confined to species from rodents and the other two show a mixture of species from birds and mammals. It is suggested that the major diversification of the main clade took place in birds, possibly in galliforms. The subsequent diversification included repeated host shifts from birds to mammals and to other birds, and from rodents to other mammals, showing that colonisation of new host lineages has been the main driver in the diversification of davaineine cestodes. It is also shown that all isolates of Inermicapsifer Janicki, 1910, mainly from rodents, form a monophyletic group positioned among Raillietina spp. in the "rodent lineage", indicating that the genus Inermicapsifer is a member of the family Davaineidae. This means that the subfamily Inermicapsiferinae and the family Inermicapsiferidae should be treated as synonyms of the Davaineidae, specifically the subfamily Davaineinae. Three additional genera generally included in the Inermicapsiferinae, i.e. Metacapsifer Spasskii, 1951, Pericapsifer Spasskii, 1951 and Thysanotaenia Beddard, 1911, are also assigned here to the Davaineidae (subfamily Davaineinae). Raillietina spp. were present in all three main lineages and appeared as multiple independent sublineages from bird and mammalian hosts, verifying the non-monophyly of the genus Raillietina and suggesting a presence of multiple new species and genera.

Evolutionary characteristics of the mitochondrial NADH dehydrogenase subunit 6 gene in some populations of four sympatric Mustela species (Mustelidae, Mammalia) from central Europe.

Selection on or reticulate evolution of mtDNA is documented in various mammalian taxa and could lead to misleading phylogenetic conclusions if not recognized. We sequenced the MT-ND6 gene of four sympatric Mustelid species of the genus Mustela from some central European populations. We hypothesised positive selection on MT-ND6, given its functional importance and the different body sizes and life histories of the species, even though climatic differences may be unimportant for adaptation in sympatry. MT-ND6 genes were sequenced in 187 sympatric specimens of weasels, Mustela nivalis, stoats, M. erminea, polecats, M. putorius, and steppe polecats, M. eversmannii, from eastern Austria and of fourteen allopatric polecats from eastern-central Germany. Median joining networks, neighbour joining and maximum likelihood analyses as well as Bayesian inference grouped all species according to earlier published phylogenetic models. However, polecats and steppe polecats, two very closely related species, shared the same two haplotypes. We found only negative selection within the Mustela sequences, including 131 downloaded ones covering thirteen species. Positive selection was observed on three MT-ND6 codons of other mustelid genera retrieved from GenBank. Negative selection for MT-ND6 within the genus Mustela suggests absence of both environmental and species-specific effects of cellular energy metabolism despite large species-specific differences in body size. The presently found shared polymorphism in European polecats and steppe polecats may result from ancestral polymorphism before speciation and historical or recent introgressive hybridization; it may indicate mtDNA capture of steppe polecats by M. putorius in Europe.

Evidence for hybridization-driven heteroplasmy maintained across generations in a ricefish endemic to a Wallacean ancient lake.

Heteroplasmy, the presence of multiple mitochondrial DNA (mtDNA) haplotypes within cells of an individual, is caused by mutation or paternal leakage. However, heteroplasmy is usually resolved to homoplasmy within a few generations because of germ-line bottlenecks; therefore, instances of heteroplasmy are limited in nature. Here, we report heteroplasmy in the ricefish species Oryzias matanensis, endemic to Lake Matano, an ancient lake in Sulawesi Island, in which one individual was known to have many heterozygous sites in the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene. In this study, we cloned the ND2 gene for some additional individuals with heterozygous sites and demonstrated that they are truly heteroplasmic. Phylogenetic analysis revealed that the extra haplotype within the heteroplasmic O. matanensis individuals clustered with haplotypes of O. marmoratus, a congeneric species inhabiting adjacent lakes. This indicated that the heteroplasmy originated from paternal leakage due to interspecific hybridization. The extra haplotype was unique and contained two non-synonymous substitutions. These findings demonstrate that this hybridization-driven heteroplasmy was maintained across generations for a long time to the extent that the extra mitochondria evolved within the new host.

Understanding the role of pigs in the transmission of zoonotic Echinococcus ortleppi in Haryana, India.

The etiological agents of zoonotic cystic echinococcosis comprise the Echinococcus granulosus sensu lato (s.l.) species complex. The present study was aimed at investigating the zoonotic genotypes of Echinococcus granulosus s.l. circulating in the pig population of Haryana, India. Out of 253 slaughtered pigs screened, 5 showed the presence of hydatid cysts. The amplification of the partial mitochondrial NADH dehydrogenase subunit 1 (nad1) gene for the molecular confirmation and phylogenetics of the retrieved metacestodes (n = 2) revealed the presence of E. ortleppi. The sequences generated herein exhibited 99.80% homology to the GenBank archived E. ortleppi sequences. Cladistics targeting genetic diversity and haplotype network analysis involved 37 E. granulosus s.l. GenBank archived sequences from India corresponding to different hosts (large and small ruminants and humans) along with the sequences (n = 2) generated in the present study. Overall, 14 haplotypes with high haplotype (0.780 ± 0.059) and low nucleotide (0.033 ± 0.010) diversities were recorded for the overall data set, which evinced a population expansion. The median-joining haplotype network revealed a stellate shape of E. granulosus sensu stricto (s.s.) sequences, which was indicative of rapid population expansion. High genetic differentiation (FST = 0.840 - 0.983) and low gene flow (Nm = 0.003 - 0.047) were recorded between the pig intermediate hosts infected with E. ortleppi and other hosts infected with E. granulosus s.s. The findings are of paramount significance for the formulation of effective control strategies considering the public health and economic impact of cystic echinococcosis.

Determining the Matrilineal Origin of Indonesian Kerinci Duck Breed (Anas platyrhynchos) Based on MT-ND2 Gene Diversity

The Kerinci duck (Anas platyrhynchos), hailing from Jambi Province, represents one of the local duck breeds of Indonesia. This study aimed to ascertain the matrilineal origin of Kerinci ducks through analysis of the mitochondrial NADH Dehydrogenase subunit 2 (MT-ND2) gene. In this pursuit, forward sequences of the MT-ND2 gene (490 bp) were extracted from unsexed Kerinci ducks, totalling forty-eight (48) sequences, procured from blood samples. The findings demonstrated the identification of fifteen (15) distinct haplotypes within the MT-ND2 gene, with corresponding haplotype diversity (Hd) and nucleotide diversity (pi) values of 0.74 and 0.003, respectively. The resulting phylogenetic tree unveiled that Kerinci ducks exhibit two matrilineal origins: an Asian and an independent Kerinci lineage. Moreover, most Kerinci ducks were categorised within the H4 group (24 birds) of the Asian lineage. Nevertheless, this study also revealed the existence of an independent Kerinci lineage comprising eight (8) duck haplotypes. In conclusion, the analysis of the MT-ND2 gene underscored the genetic introgression of A. zonorhyncha and A. poecilorhyncha in Kerinci ducks.

Src-NADH dehydrogenase subunit 2 complex and recognition memory of imprinting in domestic chicks.

Src is a non-receptor tyrosine kinase participating in a range of neuronal processes, including synaptic plasticity. We have recently shown that the amounts of total Src and its two phosphorylated forms, at tyrosine-416 (activated) and tyrosine-527 (inhibited), undergoes time-dependent, region-specific learning-related changes in the domestic chick forebrain after visual imprinting. These changes occur in the intermediate medial mesopallium (IMM), a site of memory formation for visual imprinting, but not the posterior pole of the nidopallium (PPN), a control brain region not involved in imprinting. Src interacts with mitochondrial genome-coded NADH dehydrogenase subunit 2 (NADH2), a component of mitochondrial respiratory complex I. This interaction occurs at brain excitatory synapses bearing NMDA glutamate receptors. The involvement of Src-NADH2 complexes in learning and memory is not yet explored. We show for the first time that, independently of changes in total Src or total NADH2, NADH2 bound to Src immunoprecipitated from the P2 plasma membrane-mitochondrial fraction: (i) is increased in a learning-related manner in the left IMM 1 h after the end of training; (ii), is decreased in the right IMM in a learning-related way 24 h after training. These changes occurred in the IMM but not the PPN. They are attributable to learning occurring during training rather than a predisposition to learn. Learning-related changes in Src-bound NADH2 are thus time- and region-dependent.

Molecular discrimination of G1 and G3 genotypes of Echinococcus granulosus sensu stricto obtained from human, cattle, and sheep using the mitochondrial NADH dehydrogenase subunit 5 marker

Cystic echinococcosis (CE) is a common zoonotic disease caused by the larval form of Echinococcus granulosus sensu lato. This study determined the genotype and haplotype differences using the NADH dehydrogenase subunit 5 gene in hydatid cyst samples. Human (n = 12), cattle (n = 28), and sheep (n = 31) hydatid cyst isolates were included. Seventy-one genomic DNA samples were successfully extracted, and a 759 bp mitochondrial NADH dehydrogenase subunit 5 gene fragment was amplified by PCR. Following the sequence analysis, E. granulosus sensu stricto isolates were identified as G1 (n = 61) and G3 (n = 10). A total of 23 haplotypes were obtained from the 71 E. granulosus s.s. G1 and G3 samples. The main haplotype was Hap01 (60.56 %), which consisted of the G1 genotype. The second largest haplotype was Hap04, which consisted entirely of the G3 genotype. Hap14 acted as a bridge between the G1 and G3 genotypes. This study identifies G1 as the dominant genotype in humans and farm animals in Turkey. High haplotype and nucleotide diversity in genotypes were observed. Additionally, this is the first report on the phylogeography and gene flow models of the E. granulosus s.s. population in Turkey using the NADH dehydrogenase subunit 5 gene, the best marker distinguishing between G1 and G3 genotypes.

Genetic diversity and phylogeography of Phlebotomus argentipes (Diptera: Psychodidae, Phlebotominae), using COI and ND4 mitochondrial gene sequences.

Phlebotomus argentipes complex is the primary vector for cutaneous leishmaniasis, a burgeoning health concern in contemporary Sri Lanka, where effective vector control is important for proper disease management. Understanding the genetic diversity of the P. argentipes population in Sri Lanka is vital before implementing a successful vector control program. Various studies have indicated that genetic divergence, caused by genetic drift or selection, can significantly influence the vector capacity of arthropod species. To devise innovative control strategies for P. argentipes, exploring genetic diversity and phylogeography can offer valuable insights into vector competence, key genetic trait transfer, and impact on disease epidemiology. The primary objective is to analyze the genetic diversity and phylogeography of the P. argentipes complex in Sri Lanka, based on two mitochondrial genomic regions in modern representatives of P. argentipes populations. A total of 159 P. argentipes specimens were collected from five endemic areas of cutaneous leishmaniasis and identified morphologically. Two mitochondrial regions (Cytochrome c oxidase subunit I (COI) and NADH dehydrogenase subunit 4 (ND4) were amplified using the total DNA and subsequently sequenced. Partial sequences of those mitochondrial genes were utilized to analyze genetic diversity indices and to explore phylogenetic and phylogeographic relationships. Among five sampling locations, the highest genetic diversity for COI and ND4 was observed in Hambantota (Hd-0.749, π-0.00417) and Medirigiriya (Hd-0.977, π-0.01055), respectively. Phylogeographic analyses conducted using COI sequences and GenBank retrieved sequences demonstrated a significant divergence of P. argentipes haplotypes found in Sri Lanka. Results revealed that they have evolved from the Indian ancestral haplotype due to historical- geographical connections of the Indian subcontinent with Sri Lanka. Utilizing high-mutation-rate mitochondrial genes, such as ND4, can enhance the accuracy of genetic variability analysis in P. argentipes populations in Sri Lanka. The phylogeographical analysis of COI gene markers in this study provides insights into the historical geographical relationship between India and P. argentipes in Sri Lanka. Both COI and ND4 genes exhibited consistent genetic homogeneity in P. argentipes in Sri Lanka, suggesting minimal impact on gene flow. This homogeneity also implies the potential for horizontal gene transfer across populations, facilitating the transmission of genes associated with traits like insecticide resistance. This dynamic undermines disease control efforts reliant on vector control strategies.

On the sand and among the crowds: a new species of Woodworthia gecko (Reptilia: Diplodactylidae) from Auckland, Aotearoa/ New Zealand.

Woodworthia is a diverse genus of diplodactylid geckos found in Aotearoa/ New Zealand, with 17 likely species. Despite this diversity, only two species have been formally described: Woodworthia maculata (Gray, 1845) and W. chrysosiretica (Robb, 1980). In this paper, we use an integrated taxonomic approach to describe a new species of Woodworthia gecko, Woodworthia korowai sp. nov., found along the western coastline of the Auckland Region, New Zealand. Although this species occurs in duneland habitat behind a popular beach near New Zealands most populated city, it was only recognised as a distinct taxon in 2016. We describe W. korowai sp. nov. based on a suite of morphological character states and substantial genetic divergence, based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene, that distinguish it from W. maculata sensu stricto and all other known species of Woodworthia. Phylogenetic reconstruction and molecular dating place it sister to the W. maculata group, with an estimated time of divergence in the mid to late Pliocene. This gecko is one of the most geographically restricted of all Woodworthia geckos, occupying an area of less than 500 km2 within the Auckland Region. Its narrow range and coastal association make it susceptible to environmental and genetic stochasticity. Furthermore, the popularity and recreational usage of the dune system threaten its habitat. Therefore, we hope that this description will bring attention to the value of coastal environments and the unique and sensitive duneland of Te Korowai-o-Te-Tonga/ South Kaipara Peninsula and Te Oneone Rangatira/ Muriwai Beach in particular and encourage conservation efforts to protect this newly described species and its habitat.

Taxonomical analysis on subspecies of Coreocarabus fraterculus (Coleoptera: Carabidae) by molecular genetics from Korea

This study was conducted to determine if molecular genetics would confirm the various subspecies within the species Coreocarabus fraterculus in Korea. In the Korean peninsula, a total of eight subspecies of C. fraterculus have been recognized based on external morphology, and they are morphologically very similar and difficult to identify. In this study, we examined the mitochondrial NADH dehydrogenase subunit 5 (ND5) gene of four subspecies inhabiting Korea, including Palgong-san, Deogyu-san, Jiri-san, and 10 other locations. Based on the ND5 sequences, the phylogenetic history of the collected individuals was reconstructed using Neighbor-Joining, Maximum Likelihood, and Maximum Parsimony trees. All the three phylogenetic trees confirmed the occurrence of four groups in Korea corresponding to four subspecies.

A new species of Cyrtodactylus Gray, 1827 (Squamata: Gekkonidae) from the Thai-Malay Peninsula and the independent evolution of cave ecomorphology on opposite sides of the Gulf of Thailand.

An integrative taxonomic analysis recovers a distinctive new species of the gekkonid genus Cyrtodactylus Gray, 1827 from Satun Province in extreme southern Thailand as the sister species to the Cyrtodactylus intermedius group of southern Indochina, approximately 600 km to the northeast across the Gulf of Thailand. Based on 1449 base pairs of the mitochondrial gene NADH dehydrogenase subunit 2 (ND2) and its flanking tRNAs, the new species, C. disjunctus sp. nov., bears a pairwise sequence divergence from the mean divergences of the intermedius group species ranging from 17.923.6%. Three different principal component analyses (PCA) and a multiple factor analysis (MFA) recover C. disjunctus sp. nov. as a highly distinctive karst cave-adapted species based on morphology and color pattern. Its sister species relationship to the intermedius groupto which it is added herefurther underscores a growing body of analyses that have recovered a trans-Gulf of Thailand connection across the submerged Sunda Shelf between the southern Thai-Malay Peninsula and southern Indochina. Fragmented karstic archipelagos stretching across Indochina have served as foci for the independent evolution of nearly 25% of the species of Cyrtodactylus. The description of C. disjunctus sp. nov. continues to highlight the fact that karstic habitats support an ever-increasing number of threatened site-specific endemics that compose much of the reptile diversity of many Asian nations but, as of yet, most of these landscapes have no legal protection.

Another new species of Dixonius (Squamata, Gekkonidae) from Gia Lai Province in the Central Highlands, Vietnam

Another new species of Dixonius, D. fulbrightisp. nov., is described from Gia Lai Province, in the Central Highlands of Vietnam, using an integrated approach based on morphological, categorical (color pattern), and mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and its flanking tRNAs data. Phylogenetic analyses recovered Dixonius fulbrightisp. nov. as closely related to D. gialaiensis from Gia Lai Province and part of a clade that includes D. minhlei, D. siamensis, and D. somchanhae. Multivariate (PCA, DAPC, and MFA) and univariate (ANOVA) analyses of 15 meristic (scale counts), six morphometric (mensural), and five categorical (color pattern and morphology) characters from 44 specimens of all eight species of Dixonius from Vietnam, Laos, and Cambodia clearly demonstrated that Dixonius fulbrightisp. nov. is statistically different and diagnostically distinct from all closely related species of Dixonius. This new species discovery highlights the underestimated gecko diversity and the importance of continued fieldwork in the Central Highlands of Vietnam.

First molecular data on the human roundworm Ascaris lumbricoides species complex from the Bronze and Iron Age in Hallstatt, Austria

Palaeoparasitological studies can provide valuable information on the emergence, distribution, and elimination of parasites during a particular time in the past. In the prehistoric salt mines of Hallstatt, located in the Austrian Alps, human faeces have been conserved in salt. The aim of this study was to recover ancient DNA of intestinal parasites from these coprolites. Altogether, 35 coprolites from the Hallstatt salt mines, dating back to the Bronze Age mining phase (1158–1063 BCE) and the Iron Age mining phase (750–662 BCE), respectively, were analysed by microscopy and molecular methods. In 91% of the coprolite samples, eggs of soil-transmitted helminths (STH), namely of Trichuris and/or Ascaris were detected by light microscopy. The Ascaris eggs were exceptionally well preserved. For further analysis, DNA was extracted from the palaeofaecal samples and species-specific primers targeting different genes were designed. While amplification of Trichuris DNA remained unsuccessful, sequence data of A. lumbricoides species complex were successfully obtained from 16 coprolites from three different genes, the mitochondrial cytochrome c oxidase subunit 1 gene (cox1), the mitochondrial cytochrome B gene (cytB) and the mitochondrial NADH dehydrogenase subunit 1 gene (nadh1). Importantly, these included two Ascaris sequences from a coprolite from the Bronze Age, which to the best of our knowledge are the first molecular data of this genus from this period.

Southbound - the southernmost record of Tylototriton (Amphibia, Caudata, Salamandridae) from the Central Highlands of Vietnam represents a new species.

A new species of the genus Tylototriton is described from Ngoc Linh Mountain, Kon Tum Province, in the Central Highlands of Vietnam based on integrative taxonomy, namely by combining molecular and morphological evidence. Tylototritonngoclinhensissp. nov. differs from all other congeners based on morphological data, allopatric distribution, and molecular divergence. In terms of genetic divergence, Tylototritonngoclinhensissp. nov. distinctly differs from the sister species T.panhai (6.77%) and from T.ngarsuensis (12.36%) based on the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene. Tylototritonngoclinhensissp. nov. is a moderate sized and robust salamander species with large cephalic edges, parotoids, and vertebral ridge orange in coloration. The new taxon differs from its congeners by a combination of the following morphological characteristics: size medium (SVL 60.8-66.5 mm, TL 57.6-61.8 mm in males, and SVL 72.5-75.6 mm, TL 62.9-67.9 mm in females); head longer than wide; parotoids very prominent and enlarged, projecting backwards; tail length shorter than snout-vent length; vertebral ridge large, high and glandular in appearance; 14 large and distinct dorsolateral glandular warts; gular fold present; tips of fore and hind limbs overlapping when adpressed along the body; tips of fingers reaching between eye and nostril when foreleg is laid forward; dorsal surface and lateral sides of the head, upper and lower lips, dorsolateral glandular warts, vertebral ridge, the peripheral area of the cloaca and the ventral edge of the tail orange in coloration; the presence of a distinct black line extending from the posterior end of the eye towards the shoulder. Tylototritonngoclinhensissp. nov. is restricted to evergreen montane forests near water bodies on Ngoc Linh Mountain. We suggest that the new species should be classified as Endangered (EN) in the IUCN Red List. This new important discovery represents the eighth Tylototriton taxon described from Vietnam, and at the same time constitutes the southernmost distributional record for the whole genus in Asia.

A new species of Hemiphyllodactylus (Squamata, Gekkonidae) from Ha Giang Province, Vietnam.

An integrative analysis recovered a new species of the Hemiphyllodactylustypus group from a karst formation in Lung Cu Commune, Dong Van District, Ha Giang Province, northeastern Vietnam. Hemiphyllodactyluslungcuensissp. nov. is embedded within clade 6 of the typus group, bearing an uncorrected pairwise sequence divergence of 4.6-20.2% from all other species based on a 1,038 base pair segment of the mitochondrial NADH dehydrogenase subunit 2 gene (ND2). It is diagnosable from other species in clade 6 by statistically significant mean differences in normalized morphometric, meristic, and categorical characters. A multiple factor analysis using the three aforementioned character types recovered its unique, non-overlapping placement in morphospace as statistically significantly different from that of all other species in clade 6. The description of this new Hemiphyllodactylus species contributes to a growing body of literature underscoring the high degree of herpetological diversity and endemism in karst landscapes in Vietnam as well as in the genus Hemiphyllodactylus.

A new species of the Cyrtodactylusbrevipalmatus group (Squamata, Gekkonidae) from Tak Province, northwestern Thailand.

An integrative taxonomic analysis was used to delimit and diagnose a new species of the Cyrtodactylusbrevipalmatus group from Tak Province in western Thailand. Although Bayesian phylogenetic analyses place C.denticulatussp. nov. within the brevipalmatus group, the new species is neither nested within nor is it the sister species of any other species in the brevipalmatus group. Furthermore, based on the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs, it bears an uncorrected pairwise sequence divergence of 7.87-21.94% from all other species in the brevipalmatus group. Cyrtodactylusdenticulatussp. nov. is differetiated from all other species in the brevipalmatus group by having a number of unique charateristics such as denticulate ventrolateral body folds and ventrolateral subcaudal ridges, characters not seen in any other species of the group (n = 51 individuals). Additionally, based on a multiple factor anlaysis, C.denticulatussp. nov. does not overlap with any other species in multivariate space. The discovery of C.denticulatussp. nov. underscores the unrealized diversity of upland ecosystems across Thailand and the urgent need for increased exploration and conservation of these unique imperiled montane refugia, especially in this era of climate change.

Two new species of Dixonius from Vietnam and Laos with a discussion of the taxonomy of Dixonius (Squamata, Gekkonidae).

Integrated analyses using maximum likelihood (ML), Bayesian inference (BI), principal component analysis (PCA), discriminate analysis of principal components (DAPC), multiple factor analysis (MFA), and analysis of variance (ANOVA) recovered two new diagnosable species of gekkonid lizards in the genus Dixonius, one from the Central Highlands, Gia Lai Province, Vietnam and another from the Vientiane Province, Laos. Phylogenetic analyses based on the mitochondrial NADH dehydrogenase subunit 2 gene (ND2) and adjacent tRNAs showed that Dixoniusgialaiensissp. nov. is the sister species of D.minhlei from Dong Nai Province, Vietnam and is nested within a clade that also includes the sister species D.siamensis and D.somchanhae. Dixoniusmuangfuangensissp. nov. is the sister species to D.lao from Khammouane Province, Laos and is embedded in a clade with D.vietnamensis, D.taoi, and undescribed species from Thailand. Multivariate (PCA, DAPC, and MFA) and univariate (ANOVA) analyses using combinations of 15 meristic (scale counts), six morphometric (measurements), and five categorical (color pattern and morphology) characters from 44 specimens encompassing all eight species of Dixonius from Vietnam and Laos clearly illustrate Dixoniusgialaiensissp. nov. and Dixoniusmuangfuangensissp. nov. are statistically different and discretely diagnosable from all closely related species of Dixonius. These integrative analyses also highlight additional taxonomic issues that remain unresolved within Dixonius and the need for additional studies. The discovery of these new species further emphasizes the underappreciated herpetological diversity of the genus Dixonius and illustrates the continued need for field work in these regions.