Polyploidization of Indotyphlops braminus: evidence from isoform-sequencing.

BACKGROUND: Indotyphlops braminus, the only known triploid parthenogenetic snake, is a compelling species for revealing the mechanism of polyploid emergence in vertebrates. METHODS: In this study, we applied PacBio isoform sequencing technology to generate the first full-length transcriptome of I. braminus, aiming to improve the understanding of the molecular characteristics of this species. RESULTS: A total of 51,849 nonredundant full-length transcript assemblies (with an N50 length of 2980 bp) from I. braminus were generated and fully annotated using various gene function databases. Our analysis provides preliminary evidence supporting a recent genome duplication event in I. braminus. Phylogenetic analysis indicated that the divergence of I. braminus subgenomes occurred approximately 11.5 ~ 15 million years ago (Mya). The full-length transcript resource generated as part of this research will facilitate transcriptome analysis and genomic evolution studies in the future.

The macroevolutionary singularity of snakes.

Snakes and lizards (Squamata) represent a third of terrestrial vertebrates and exhibit spectacular innovations in locomotion, feeding, and sensory processing. However, the evolutionary drivers of this radiation remain poorly known. We infer potential causes and ultimate consequences of squamate macroevolution by combining individual-based natural history observations (>60,000 animals) with a comprehensive time-calibrated phylogeny that we anchored with genomic data (5400 loci) from 1018 species. Due to shifts in the dynamics of speciation and phenotypic evolution, snakes have transformed the trophic structure of animal communities through the recurrent origin and diversification of specialized predatory strategies. Squamate biodiversity reflects a legacy of singular events that occurred during the early history of snakes and reveals the impact of historical contingency on vertebrate biodiversity.

Molecular data reveals a new genus of blindsnakes within Asiatyphlopinae from India.

The genus Indotyphlops has a widespread distribution in the Indian landmass and Southeast Asia, with 20 reported species. The current classification within the genus is based on morphology. In this study, we sampled all the reported Indotyphlops species from subcontinental India, to resolve relationships within this genus and to understand biogeographic patterns that resulted in the widespread distribution. We generated sequences for five nuclear markers which were used in the global typhlopoid phylogeny and built phylogenetic trees of the superfamily Typhlopoidea. We also carried out divergence time analysis and biogeographic analysis to understand the time and modes of dispersal and diversification of these species. The results show Indotyphlops sensu lato to be polyphyletic, with the clade consisting of I. porrectus and I. exiguus sister to a clade consisting of the southeast Asian typhlopid genera Ramphotyphlops, Anilios, Malayotyphlops, Acutotyphlops, Sundatyphlops, and Indotyphlops sensu stricto. The other clade consists of I. pammeces and I. braminus from the Indian subcontinent and I. albiceps from Southeast Asia. Biogeographical analysis suggests two dispersals from Asia to the Indian landmass-an earlier dispersal from Eurasia into India led to the lineage consisting of I. porrectus and I. exiguus, followed by a later dispersal that evolved into I. pammeces and I. braminus. These results necessitate a taxonomic revision. We propose the genus Pseudoindotyphlops gen. nov. for the clade currently consisting of the most recent common ancestor (MRCA) of I. porrectus and I. exiguus, and all descendants thereof.

It's a trap?! Escape from an ancient, ancestral sex chromosome system and implication of Foxl2 as the putative primary sex-determining gene in a lizard (Anguimorpha; Shinisauridae).

Although sex determination is ubiquitous in vertebrates, mechanisms of sex determination vary from environmentally to genetically influenced. In vertebrates, genetic sex determination is typically accomplished with sex chromosomes. Groups like mammals maintain conserved sex chromosome systems, while sex chromosomes in most vertebrate clades are not conserved across similar evolutionary timescales. One group inferred to have an evolutionarily stable mode of sex determination is Anguimorpha, a clade of charismatic taxa including monitor lizards, Gila monsters, and crocodile lizards. The common ancestor of extant anguimorphs possessed a ZW system that has been retained across the clade. However, the sex chromosome system in the endangered, monotypic family of crocodile lizards (Shinisauridae) has remained elusive. Here, we analyze genomic data to demonstrate that Shinisaurus has replaced the ancestral anguimorph ZW system on LG7 with a novel ZW system on LG3. The linkage group, LG3, corresponds to chromosome 9 in chicken, and this is the first documented use of this syntenic block as a sex chromosome in amniotes. Additionally, this ~1 Mb region harbors approximately 10 genes, including a duplication of the sex-determining transcription factor, Foxl2, critical for the determination and maintenance of sexual differentiation in vertebrates, and thus a putative primary sex-determining gene for Shinisaurus.

Regionalization of the vertebral column and its correlation with heart position in snakes: Implications for evolutionary pathways and morphological diversification.

Spinal regionalization has important implications for the evolution of vertebrate body plans. We determined the variation in the number and morphology of vertebrae across the vertebral column (i.e., vertebral formula) for 63 snake species representing 13 families using intracolumnar variation in vertebral shape. Vertebral counts were used to determine the position of the heart, pylorus, and left kidney for each species. Across all species we observed a conspicuous midthoracic transition in vertebral shape, indicating four developmental domains of the precloacal vertebral column (cervical, anterior thoracic, posterior thoracic, and lumbar). Using phylogenetic analyses, the boundary between the anterior and posterior thoracic vertebrae was correlated with heart position. No associations were found between shifts in morphology of the vertebral column and either the pylorus or left kidney. We observed that among taxa, the number of preapex and postapex vertebrae could change independently from one another and from changes in the total number of precloacal vertebrae. Ancestral state reconstruction of the preapex and postapex vertebrae illustrated several evolutionary pathways by which diversity in the vertebral column and heart position have been attained. In addition, no conspicuous pattern was observed among the heart, pylorus, or kidney indicating that their relative positions to each other evolve independently. We conclude that snakes exhibit four morphologically distinct regions of the vertebral column. We discuss the implications of the forebody and hindbody vertebral formula on the morphological diversification of snakes.

Ecological factors and parity mode correlate with genome size variation in squamate reptiles.

BACKGROUND: Evidence of correlation between genome size, the nuclear haploid DNA content of a cell, environmental factors and life-history traits have been reported in many animal species. Genome size, however, spans over three orders of magnitude across taxa and such a correlation does not seem to follow a universal pattern. In squamate reptiles, the second most species-rich order of vertebrates, there are currently no studies investigating drivers of genome size variability. We run a series of phylogenetic generalized least-squares models on 227 species of squamates to test for possible relationships between genome size and ecological factors including latitudinal distribution, bioclimatic variables and microhabitat use. We also tested whether genome size variation can be associated with parity mode, a highly variable life history trait in this order of reptiles. RESULTS: The best-fitting model showed that the interaction between microhabitat use and parity mode mainly accounted for genome size variation. Larger genome sizes were found in live-bearing species that live in rock/sand ecosystems and in egg-laying arboreal taxa. On the other hand, smaller genomes were found in fossorial live-bearing species. CONCLUSIONS: Environmental factors and species parity mode appear to be among the main parameters explaining genome size variation in squamates. Our results suggest that genome size may favour adaptation of some species to certain environments or could otherwise result from the interaction between environmental factors and parity mode. Integration of genome size and genome sequencing data could help understand the role of differential genome content in the evolutionary process of genome size variation in squamates.

Hiding on jagged karst pinnacles: A new microendemic genus and species of a limestone-dwelling agamid lizard (Squamata: Agamidae: Draconinae) from Khammouan Province, Laos.

We describe a unique new species and genus of agamid lizard from the karstic massifs of Khammouan Province, central Laos. Laodracon carsticola Gen. et sp. nov. is an elusive medium-sized lizard (maximum snout-vent length 101 mm) specifically adapted to life on limestone rocks and pinnacles. To assess the phylogenetic position of the new genus amongst other agamids, we generated DNA sequences from two mitochondrial gene fragments (16S rRNA and ND2) and three nuclear loci ( BDNF, RAG1 and c-mos), with a final alignment comprising 7 418 base pairs for 64 agamid species. Phylogenetic analyses unambiguously place the new genus in the mainland Asia subfamily Draconinae, where it forms a clade sister to the genus Diploderma from East Asia and the northern part of Southeast Asia. Morphologically, the new genus is distinguished from all other genera in Draconinae by possessing a notably swollen tail base with enlarged scales on its dorsal and ventral surfaces. Our work provides further evidence that limestone regions of Indochina represent unique "arks of biodiversity" and harbor numerous relict lineages. To date, Laodracon carsticola Gen. et sp. nov. is known from only two adult male specimens and its distribution seems to be restricted to a narrow limestone massif on the border of Khammouan and Bolikhamxai provinces of Laos. Additional studies are required to understand its life history, distribution, and conservation status.

Genomic evidence sheds new light on phylogeny of Rhabdophis nuchalis (sensu lato) complex (Serpentes: Natricidae).

Stable taxonomy and robust phylogeny are essential for the evolution and conservation of organisms. The Rhabdophis nuchalis (sensu lato) complex presently contains three species (R. nuchalis, R. chiwen, R. pentasupralabialis). Although several studies have explored the diversity and phylogeography of this group, certain issues related to systematics and taxonomy remain unresolved. Here, based on genome-wide data, including single nucleotide polymorphisms (SNPs) generated from ddRAD-seq and mitochondrial DNA (mtDNA), we re-evaluated the phylogenetic relationships and cryptic diversity of this species group. Our results are generally consistent with previous studies but provide some new insights. Phylogenetic relationship reconstruction based on SNPs and mtDNA revealed that three species in the R. nuchalis (sensu lato) complex did not form a monophyly but each species is well supported as monophyletic lineage in SNP-based analyses. Population structure analyses showed genetic admixture between several species pairs. Additionally, the population in eastern Yunnan, China, was identified as a potential cryptic species and thus described as a new species based on morphological data. From our results and previous studies, we redefined the distribution boundary for each species in the R. nuchalis (sensu lato) species complex.

Domain loss enabled evolution of novel functions in the snake three-finger toxin gene superfamily.

Three-finger toxins (3FTXs) are a functionally diverse family of toxins, apparently unique to venoms of caenophidian snakes. Although the ancestral function of 3FTXs is antagonism of nicotinic acetylcholine receptors, redundancy conferred by the accumulation of duplicate genes has facilitated extensive neofunctionalization, such that derived members of the family interact with a range of targets. 3FTXs are members of the LY6/UPAR family, but their non-toxin ancestor remains unknown. Combining traditional phylogenetic approaches, manual synteny analysis, and machine learning techniques (including AlphaFold2 and ProtT5), we have reconstructed a detailed evolutionary history of 3FTXs. We identify their immediate ancestor as a non-secretory LY6, unique to squamate reptiles, and propose that changes in molecular ecology resulting from loss of a membrane-anchoring domain and changes in gene expression, paved the way for the evolution of one of the most important families of snake toxins.

The State of Squamate Genomics: Past, Present, and Future of Genome Research in the Most Speciose Terrestrial Vertebrate Order.

Squamates include more than 11,000 extant species of lizards, snakes, and amphisbaenians, and display a dazzling diversity of phenotypes across their over 200-million-year evolutionary history on Earth. Here, we introduce and define squamates (Order Squamata) and review the history and promise of genomic investigations into the patterns and processes governing squamate evolution, given recent technological advances in DNA sequencing, genome assembly, and evolutionary analysis. We survey the most recently available whole genome assemblies for squamates, including the taxonomic distribution of available squamate genomes, and assess their quality metrics and usefulness for research. We then focus on disagreements in squamate phylogenetic inference, how methods of high-throughput phylogenomics affect these inferences, and demonstrate the promise of whole genomes to settle or sustain persistent phylogenetic arguments for squamates. We review the role transposable elements play in vertebrate evolution, methods of transposable element annotation and analysis, and further demonstrate that through the understanding of the diversity, abundance, and activity of transposable elements in squamate genomes, squamates can be an ideal model for the evolution of genome size and structure in vertebrates. We discuss how squamate genomes can contribute to other areas of biological research such as venom systems, studies of phenotypic evolution, and sex determination. Because they represent more than 30% of the living species of amniote, squamates deserve a genome consortium on par with recent efforts for other amniotes (i.e., mammals and birds) that aim to sequence most of the extant families in a clade.

Large-scale snake genome analyses provide insights into vertebrate development.

Snakes are a remarkable squamate lineage with unique morphological adaptations, especially those related to the evolution of vertebrate skeletons, organs, and sensory systems. To clarify the genetic underpinnings of snake phenotypes, we assembled and analyzed 14 de novo genomes from 12 snake families. We also investigated the genetic basis of the morphological characteristics of snakes using functional experiments. We identified genes, regulatory elements, and structural variations that have potentially contributed to the evolution of limb loss, an elongated body plan, asymmetrical lungs, sensory systems, and digestive adaptations in snakes. We identified some of the genes and regulatory elements that might have shaped the evolution of vision, the skeletal system and diet in blind snakes, and thermoreception in infrared-sensitive snakes. Our study provides insights into the evolution and development of snakes and vertebrates.

Caecilian Genomes Reveal the Molecular Basis of Adaptation and Convergent Evolution of Limblessness in Snakes and Caecilians.

We present genome sequences for the caecilians Geotrypetes seraphini (3.8 Gb) and Microcaecilia unicolor (4.7 Gb), representatives of a limbless, mostly soil-dwelling amphibian clade with reduced eyes, and unique putatively chemosensory tentacles. More than 69% of both genomes are composed of repeats, with retrotransposons being the most abundant. We identify 1,150 orthogroups that are unique to caecilians and enriched for functions in olfaction and detection of chemical signals. There are 379 orthogroups with signatures of positive selection on caecilian lineages with roles in organ development and morphogenesis, sensory perception, and immunity amongst others. We discover that caecilian genomes are missing the zone of polarizing activity regulatorysequence (ZRS) enhancer of Sonic Hedgehog which is also mutated in snakes. In vivo deletions have shown ZRS is required for limb development in mice, thus, revealing a shared molecular target implicated in the independent evolution of limblessness in snakes and caecilians.

Differences in the luminal and mucosal gut microbiomes and metabolomes of oriental rat snake (Ptyas mucosus).

Previous studies regarding the gastrointestinal biogeography of microbiomes generally focused on longitudinal comparisons, whereas few studies have compared luminal and mucosal microbiomes. Investigations of the snake gut microbiome have attracted interest because of the unique digestive physiology and hibernation behavior, but adequate sampling methods must be developed. Here, we used an omics approach combining 16S rRNA gene sequencing with untargeted metabolomics to profile the luminal and mucosal gut microbiomes and metabolomes in oriental rat snakes, with the goal of revealing the heterogeneity and co-occurrence at these sites. The α-diversity of the gut microbiome was significantly higher at mucosal sites than at luminal sites. Microbial composition also differed according to sampling site, with significant differences in the abundances of dominant phyla and genera, as well as ß-diversity clustering and distribution. Metabolome profiling revealed differences that were mainly related to cholinergic substances and nucleic acids. Analysis of variations in Kyoto Encyclopedia of Genes and Genomes functions of microbes and metabolites showed that the mucosal microbiome was more frequently involved in genetic information processing and cellular processes, whereas the luminal microbiome generally participated in metabolic regulation. Notably, we found a greater abundance of the opportunistic pathogen genus Escherichia-Shigella at luminal sites and higher levels of the lipid-regulator metabolite fenfluramine at mucosal sites. Despite the extensive differences between the two sampling sites, the results revealed similarities in terms of amplicon sequence variant composition and dominant core microbes. This pilot exploration of luminal and mucosal microbiomes and metabolites provides key insights to guide future research. KEY POINTS: • Snake luminal and mucosal microbiota was distinct in composition and function. • Metabolome profiling revealed differences related to different metabolites. • The pathogenic microbes are more likely to colonize the gut lumina.

DNA barcoding of Chinese snakes reveals hidden diversity and conservation needs.

DNA barcoding has greatly facilitated studies of taxonomy, biodiversity, biological conservation, and ecology. Here, we establish a reliable DNA barcoding library for Chinese snakes, unveiling hidden diversity with implications for taxonomy, and provide a standardized tool for conservation management. Our comprehensive study includes 1638 cytochrome c oxidase subunit I (COI) sequences from Chinese snakes that correspond to 17 families, 65 genera, 228 named species (80.6% of named species) and 36 candidate species. A barcode gap analysis reveals gaps, where all nearest neighbour distances exceed maximum intraspecific distances, in 217 named species and all candidate species. Three species-delimitation methods (ABGD, sGMYC, and sPTP) recover 320 operational taxonomic units (OTUs), of which 192 OTUs correspond to named and candidate species. Twenty-eight other named species share OTUs, such as Azemiops feae and A. kharini, Gloydius halys, G. shedaoensis, and G. intermedius, and Bungarus multicinctus and B. candidus, representing inconsistencies most probably caused by imperfect taxonomy, recent and rapid speciation, weak taxonomic signal, introgressive hybridization, and/or inadequate phylogenetic signal. In contrast, 43 species and candidate species assign to two or more OTUs due to having large intraspecific distances. If most OTUs detected in this study reflect valid species, including the 36 candidate species, then 30% more species would exist than are currently recognized. Several OTU divergences associate with known biogeographic barriers, such as the Taiwan Strait. In addition to facilitating future studies, this reliable and relatively comprehensive reference database will play an important role in the future monitoring, conservation, and management of Chinese snakes.

Genetic mapping and molecular mechanism behind color variation in the Asian vine snake.

BACKGROUND: Reptiles exhibit a wide variety of skin colors, which serve essential roles in survival and reproduction. However, the molecular basis of these conspicuous colors remains unresolved. RESULTS: We investigate color morph-enriched Asian vine snakes (Ahaetulla prasina), to explore the mechanism underpinning color variations. Transmission electron microscopy imaging and metabolomics analysis indicates that chromatophore morphology (mainly iridophores) is the main basis for differences in skin color. Additionally, we assemble a 1.77-Gb high-quality chromosome-anchored genome of the snake. Genome-wide association study and RNA sequencing reveal a conservative amino acid substitution (p.P20S) in SMARCE1, which may be involved in the regulation of chromatophore development initiated from neural crest cells. SMARCE1 knockdown in zebrafish and immunofluorescence verify the interactions among SMARCE1, iridophores, and tfec, which may determine color variations in the Asian vine snake. CONCLUSIONS: This study reveals the genetic associations of color variation in Asian vine snakes, providing insights and important resources for a deeper understanding of the molecular and genetic mechanisms related to reptilian coloration.

Ultraconserved elements-based phylogenomic systematics of the snake superfamily Elapoidea, with the description of a new Afro-Asian family.

The highly diverse snake superfamily Elapoidea is considered to be a classic example of ancient, rapid radiation. Such radiations are challenging to fully resolve phylogenetically, with the highly diverse Elapoidea a case in point. Previous attempts at inferring a phylogeny of elapoids produced highly incongruent estimates of their evolutionary relationships, often with very low statistical support. We sought to resolve this situation by sequencing over 4,500 ultraconserved element loci from multiple representatives of every elapoid family/subfamily level taxon and inferring their phylogenetic relationships with multiple methods. Concatenation and multispecies coalescent based species trees yielded largely congruent and well-supported topologies. Hypotheses of a hard polytomy were not retained for any deep branches. Our phylogenies recovered Cyclocoridae and Elapidae as diverging early within Elapoidea. The Afro-Malagasy radiation of elapoid snakes, classified as multiple subfamilies of an inclusive Lamprophiidae by some earlier authors, was found to be monophyletic in all analyses. The genus Micrelaps was consistently recovered as sister to Lamprophiidae. We establish a new family, Micrelapidae fam. nov., for Micrelaps and assign Brachyophis to this family based on cranial osteological synapomorphy. We estimate that Elapoidea originated in the early Eocene and rapidly diversified into all the major lineages during this epoch. Ecological opportunities presented by the post-Cretaceous-Paleogene mass extinction event may have promoted the explosive radiation of elapoid snakes.

A near-complete species-level phylogeny of uropeltid snakes harnessing historical museum collections as a DNA source.

Uropeltidae is a clade of small fossorial snakes (ca. 64 extant species) endemic to peninsular India and Sri Lanka. Uropeltid taxonomy has been confusing, and the status of some species has not been revised for over a century. Attempts to revise uropeltid systematics and undertake evolutionary studies have been hampered by incompletely sampled and incompletely resolved phylogenies. To address this issue, we take advantage of historical museum collections, including type specimens, and apply genome-wide shotgun (GWS) sequencing, along with recent field sampling (using Sanger sequencing) to establish a near-complete multilocus species-level phylogeny (ca. 87% complete at species level). This results in a phylogeny that supports the monophyly of all genera (if Brachyophidium is considered a junior synonym of Teretrurus), and provides a firm platform for future taxonomic revision. Sri Lankan uropeltids are probably monophyletic, indicating a single colonisation event of this island from Indian ancestors. However, the position of Rhinophis goweri (endemic to Eastern Ghats, southern India) is unclear and warrants further investigation, and evidence that it may nest within the Sri Lankan radiation indicates a possible recolonisation event. DNA sequence data and morphology suggest that currently recognised uropeltid species diversity is substantially underestimated. Our study highlights the benefits of integrating museum collections in molecular genetic analyses and their role in understanding the systematics and evolutionary history of understudied organismal groups.

Genomic evidence reveals intraspecific divergence of the hot-spring snake (Thermophis baileyi), an endangered reptile endemic to the Qinghai-Tibet plateau.

Understanding how and why species evolve requires knowledge on intraspecific divergence. In this study, we examined intraspecific divergence in the endangered hot-spring snake (Thermophis baileyi), an endemic species on the Qinghai-Tibet Plateau (QTP). Whole-genome resequencing of 58 sampled individuals from 15 populations was performed to identify the drivers of intraspecific divergence and explore the potential roles of genes under selection. Our analyses resolved three groups, with major intergroup admixture occurring in regions of group contact. Divergence probably occurred during the Pleistocene as a result of glacial climatic oscillations, Yadong-Gulu rift, and geothermal fields differentiation, while complex gene flow between group pairs reflected a unique intraspecific divergence pattern on the QTP. Intergroup fixed loci involved selected genes functionally related to divergence and local adaptation, especially adaptation to hot spring microenvironments in different geothermal fields. Analysis of structural variants, genetic diversity, inbreeding, and genetic load indicated that the hot-spring snake population has declined to a low level with decreased diversity, which is important for the conservation management of this endangered species. Our study demonstrated that the integration of demographic history, gene flow, genomic divergence genes, and other information is necessary to distinguish the evolutionary processes involved in speciation.

A systematic review of snake translocations to identify potential tactics for reducing postrelease effects.

Advancements in the field of reintroduction biology are needed, but understanding of how to effectively conduct translocations, particularly with snakes, is lacking. We conducted a systematic review of snake translocation studies to identify potential tactics for reducing postrelease effects. We included studies on intentional, human-mediated, wild-wild, or captive-wild translocations to any location, regardless of motive or number of snakes translocated. Only studies that presented results for at least 1 of 4 outcomes (movement behavior, site fidelity, survival, or population establishment) were included. We systematically searched 4 databases for published studies and used 5 methods to search the gray literature. Our search and screening criteria yielded 121 data sources, representing 130 translocation cases. We quantified the association between 15 translocation tactics and short-term translocation outcomes by calculating odds ratios and used forest plots to display results. Snake translocations involved 47 species (from mainly 2 families), and most were motivated by research, were monitored for at least 6 months, occurred in North America, and took place from the 1990s onward. The odds of a positive snake translocation outcome were highest with release of captive reared or juvenile snakes, release of social groups together, delayed release, provision of environmental enrichment or social housing before release, or minimization of distance translocated. The odds of a positive outcome were lowest when snakes were released early in their active season. Our results do not demonstrate causation, but outcomes of snake translocation were associated with 8 tactics (4 of which were strongly correlated). In addition to targeted comparative studies, we recommend practitioners consider the possible influence of these tactics when planning snake translocations.

La biología de la reintroducción requiere de avances; sin embargo, hay muy poco conocimiento sobre cómo realizar efectivamente las reubicaciones, particularmente las de las serpientes. Revisamos sistemáticamente los estudios sobre reubicación de serpientes para identificar las potenciales maniobras de reducción del estrés postliberación. Incluimos estudios sobre las reubicaciones a cualquier localidad que hayan sido intencionales, mediadas por humanos, de ambiente silvestre a ambiente silvestre o de cautiverio a ambiente silvestre sin importar el motivo o el número de serpientes reubicadas. Sólo incluimos estudios que presentaran resultados para al menos 1 de los cuatro resultados posibles: conducta de movimiento, fidelidad al sitio, supervivencia o establecimiento poblacional. Buscamos sistemáticamente en cuatro bases de datos de estudios publicados y usamos cinco métodos para buscar en la literatura gris. Nuestros criterios de búsqueda y revisión resultaron en 121 fuentes de datos, las cuales representaron 130 casos de reubicación. Cuantificamos la asociación entre 15 maniobras de reubicación y los resultados a corto plazo de las reubicaciones mediante el cálculo de la razón de probabilidades y usamos diagramas de efecto para mostrar los resultados. La reubicación de serpientes incluyó a 47 especies (principalmente de dos familias) y la mayoría estuvo motivada por la investigación, fue monitoreada durante seis meses (al menos), se ubicó en América del Norte y ocurrieron a partir de la década de 1990. La probabilidad de que la reubicación de serpientes tuviera un resultado positivo fueron mayores con la liberación de serpientes criadas o juveniles, la liberación de grupos sociales en conjunto, la liberación retardada, el suministro de enriquecimiento ambiental o alojamiento previo a la liberación o la reducción de la distancia de reubicación. Esta misma probabilidad fue menor cuando las serpientes fueron liberadas tempranamente durante su temporada activa. Nuestros resultados no demuestran causalidad, pero los resultados de la reubicación de serpientes estuvieron asociados con ocho maniobras (cuatro de las cuales contaban con una correlación sólida). Además de los estudios comparativos focalizados, recomendamos que los practicantes consideren la posible influencia de estas maniobras cuando se planifiquen la reubicación de serpientes.

Phylogeography of cliff racer (Platyceps rhodorachis Jan, 1865) from Punjab, Pakistan / Filografia de penhasco (Platyceps rhodorachis Jan, 1865) de Punjab, Paquistão

The present study reports the existence of cliff racer, Platyceps rhodorachis from the plains of Punjab, Pakistan. A total of 10 specimens were captured during the field surveys from June to September, 2018 from different sites of Punjab. Platyceps rhodorachis was identify on the basis of morphology and confirmed through COI gene sequences. The obtained DNA sequences have shown reliable and exact species identification. Newly produced DNA sequences of Platyceps rhodorachis were submitted to GenBank and accession numbers were obtained (MK936174.1, MK941839.1 and MT790210.1). N-J tree based on COI sequences of Platyceps rhodorachis clearly separated as out-group with other members of family Colubridae based on p-distance. The intra-specific genetic variation ranges from 12% to 18%. The DNA sequences of Platyceps rhodorachis kashmirensis, Platyceps rhodorachis ladacensis, Platyceps ventromaculatus, Platyceps ventromaculatus bengalensis and Platyceps ventromaculatus indusai are not available at NCBI to validate their taxonomic positions. In our recommendations, a large scale molecular based identification of Pakistan’s herpetofauna is required to report more new or subspecies from country.

O presente estudo relata a existência de um corredor de penhasco, Platyceps rhodorachis, das planícies de Punjab, Paquistão. Um total de 10 espécimes foi capturado durante os levantamentos de campo de junho a setembro de 2018 em diferentes locais de Punjab. Platyceps rhodorachis foi identificada com base na morfologia e confirmada por meio de sequências do gene COI. As sequências de DNA obtidas mostraram identificação de espécies confiável e exata. Sequências de DNA de Platyceps rhodorachis recém-produzidas foram submetidas ao GenBank e os números de acesso foram obtidos (MK936174.1, MK941839.1 e MT790210.1). Árvore N-J baseada em sequências COI de Platyceps rhodorachis claramente separadas como out-group com outros membros da família Colubridae com base na distância-p. A variação genética intraespecífica varia de 12% a 18%. As sequências de DNA de Platyceps rhodorachis kashmirensis, Platyceps rhodorachis ladacensis, Platyceps ventromaculatus, Platyceps ventromaculatus bengalensis e Platyceps ventromaculatus indusai não estão disponíveis no NCBI para validar suas posições taxonômicas. Em nossas recomendações, uma identificação de base molecular em grande escala da herpetofauna do Paquistão é necessária para relatar mais novas ou subespécies do país.