Snake Genus Research Articles

A snake genus new to the reptile list of Lebanon: Genetic affiliation and distribution of Letheobia simoni (Boettger, 1879).

A snake genus new to the reptile list of Lebanon: Genetic affiliation and distribution of Letheobia simoni (Boettger, 1879).

A new species of Uropeltis Cuvier, 1829 (Serpentes: Uropeltidae) from the eastern escarpment of the southern Western Ghats, India.

A new species of the uropeltid ('shieldtail') snake genus Uropeltis is described based on eight specimens from the southern part of peninsular India's Western Ghats. Uropeltis caudomaculata sp. nov. is phenotypically and genetically most similar to U. pulneyensis (Beddome, 1863), but differs primarily in having more ventral scales and in being restricted to the eastern escarpment of the Western Ghats between Meghamalai and approximately 15 km East of Munnar rather than in the Palani Hills, as well as differing in DNA nucleotide sequences. From verified records, we consider U. pulneyensis to be known thus far only from the Palani Hills, and we designate a lectotype for the species. Reconsideration of the holotype of Silybura guentheri Beddome, 1878 from Meghamalai leads us to conclude that it should be removed from the subjective junior synonymy of U. pulneyensis and be considered a distinct though very poorly known species, Uropeltis guentheri comb. nov.

Two new species of the shieldtail snake genus Rhinophis Hemprich, 1820 (Serpentes: Uropeltidae), from the Rakwana and the Knuckles Massifs of Sri Lanka.

Two new species of the uropeltid snake genus Rhinophis Hemprich, 1820 are described from Sri Lanka. Rhinophis martin sp. nov. is described from 11 type specimens from the Rakwana Massif, and another 22 specimens from the same region are referred to this new species. Rhinophis dinarzardae sp. nov. is described from eight type specimens from the Knuckles Massif, and another 64 specimens from the Knuckles and adjacent hills are referred to this new species. Rhinophis martin sp. nov. has apparently not been reported previously under any scientific name, but is distinct in scalation, colour pattern and DNA. Rhinophis dinarzardae sp. nov. has long-been confused with the superficially similar R. philippinus, from which it differs by having more ventral scales, by occurring in the northern part of the Knuckles Massif and adjacent hills to the West rather than in the Central Highlands upland region (and possibly areas to the South and West) of Sri Lanka, and in DNA sequence data. The new descriptions take the inventory of currently recognised, named uropeltid species in Sri Lanka to 20, all members of the genus Rhinophis.

Nomenclatural problems raised by the recent description of a new anaconda species (Squamata, Serpentes, Boidae), with a nomenclatural review of the genus Eunectes

A recent paper proposing taxonomic changes in the South American snake genus Eunectes Wagler, 1830 (anacondas) is analysed. This paper raises an unusually high number of taxonomic and nomenclatural problems. The work does not rely on an explicit species concept, the analysis of the molecular data based on three mitochondrial genes is shown to be unreliable, and the validity of the ‘clades’ proposed in this work is questioned. The nomen proposed for a purported new species is a nomen nudum (nomenclaturally unavailable), and the designation of a ‘lectotype’ for the nominal species Eunectes murinus (Linnaeus, 1758) is invalid. We provide a review of the nomenclatural status of 18 nominal species (including four unavailable ones) once or still now referred to the genus Eunectes, we identify their ‘types’ (nomen-bearing specimens), we designate five lectotypes, which are all specimens figured and briefly described in ancient publications, and we explain the rationale behind this action, which will allow the subsequent designation as neotypes of recently collected specimens associated with precise type localities and molecular data. We show that the generic nomen Eunectes Wagler, 1830 does not apply to the taxonomic genus accommodating anacondas but, this nomen having been used for these giant and spectacular snakes for about 200 years and being well-known even outside the field of taxonomy, we argue that its traditional use should be maintained through an action of the International Commission of Zoological Nomenclature using its plenary power. Finally, we provide various recommendations regarding nomenclatural actions and publications presenting them.

A new record and a novel morph description of Boigastoliczkae (Squamata, Colubridae) from China.

The Asian Cat Snake genus Boiga Fitzinger, 1826 includes 37 species, with high species diversity. Five species of Boiga have been recorded in China including B.multomaculata (Boie, 1827), B.kraepelini (Stejneger, 1902), B.cyanea (Duméril, Bibron & Duméril, 1854), B.guangxiensis (Wen, 1998) and B.siamensis (Nutaphand, 1971). Previously, the validity of the species Boigastoliczkae (Wall, 1909) was controversial. B.stoliczkae was considered in synonymy with B.ochracea. Currently, the taxonomy of B.multomaculata and B.ochracea (Theobald, 1868) was revised so that B.multomaculata and B.ochracea actually represent a single species and B.stoliczkae was recognised as a valid species. B.stoliczkae was previously known to be found in the west from central Nepal through Darjeeling, Sikkim and Bhutan to Arunachal Pradesh and Assam in north-eastern India. One adult female specimen of the Asian Cat Snake was collected from Gyirong County, near the China-Nepal border, Tibet, China during fieldwork on August 2023. We compared morphology and mitochondrial DNA sequence data with all the species of the genus Boiga. Both datasets strongly supported referring the Chinese specimens to B.stoliczkae (Wall, 1909) due to the 21 mid-dorsal scale rows and the uncorrected p-distance (mitochondrial DNA gene cytochrome b) between this specimen and B.stoliczkae which is 1.7%. We further described morphological characters of the Chinese specimen in detail and compared these with the specimens that had been previously described. The dorsal ground colour of the Chinese specimen is dark brown, with a black stripe distributed almost evenly across the tail. This is a novel morph of the species B.stoliczkae. The newly-collected Chinese specimen expands the distribution of the species on the Himalaya range.

Reappraisal of the systematics of two sympatric coral snakes (Reptilia: Elapidae) from Northeast India

Systematics of the Asian coral snake genus Sinomicrurus Slowinski et al., 2001, was recently reviewed; however, the lack of molecular data for S. macclellandi (Reinhardt, 1844), especially topotypical specimens, renders most taxonomic revisions mutable. This largely hinders the reappraisal of the putative synonyms of S. macclellandi which may be distinct and deserve recognition to highlight their evolutionary importance and eventual conservation. We reassessed the systematic status of Northeast Indian populations of S. macclellandi that also included topotypic material, based on the combination of morphology and genetic data (mitochondrial and nuclear genes). We uncovered morphological and genetic evidence for resurrecting S. gorei comb. nov., from the synonymy of S. macclellandi and elevating it to a full species rank, previously recognised as a colour variant of S. macclellandi. We redescribed the species based on a total of 36 adult specimens examined from Mizoram, along with the type material from Assam, as well as specimens from Bangladesh. Apart from the genetic distinction of S. gorei from the other congeners, it is also morphologically diagnosable from its closest sympatric species S. macclellandi var. typica, in bearing a suit of somatic and osteological features.

Taxonomic revision of the giant marine snake genus Pterosphenus Lucas, 1898, based on new fossil material from the middle Eocene (Bartonian) Harudi Formation of Kachchh (Kutch) Basin, India

ABSTRACT Fossil snakes of the family Palaeophiidae are primarily known from rare, isolated vertebrae, leading to a poor understanding of the intra- and inter-columnar variation within a palaeophiid species. This leads to ambiguity in the taxonomic identity of these snakes, as in the case of the Eocene-age marine snakes of the genus Pterosphenus, in which the majority of species have been described by characters of problematic taxonomic value. Here, we propose a taxonomic revision of the genus based on an articulated to semi-articulated section of the vertebral column at the anterior to mid trunk-transition of Pterosphenus schucherti discovered from the middle Eocene (Bartonian) Harudi Formation, Kachchh (Kutch) Basin. The characters that separate Pterosphenus schucherti from ‘Pterosphenus schweinfurthi’ and ‘Pterosphenus biswasi,’ viz., the height of the pterapophysis and the anterior concavity of the zygosphene, have been found to be non-diagnostic, and the latter two species have been synonymized with the type species. Additionally, we utilized 2D and 3D landmark-based geometric morphometry to determine the morphometric affinity of palaeophiids amongst the alethinophidian snakes. The body size of the snake was estimated based on extant snakes with a morphometric affinity to Palaeophiidae. The cosmopolitan distribution of Pterosphenus schucherti is modelled based on the sea surface temperature (SST) constraints of the modern cosmopolitan snake Hydrophis platurus, and the known fossil localities of the species. The present findings provide crucial insights into the global paleoecological landscape of the Eocene, and the interactions of Pterosphenus schucherti with other palaeophiid snakes as well as the other Eocene fauna.

Discovery of a human monoclonal antibody that cross-neutralizes venom phospholipase A2s from three different snake genera

Despite the considerable global impact of snakebite envenoming, available treatments remain suboptimal. Here, we report the discovery of a broadly-neutralizing human monoclonal antibody, using a phage display-based cross-panning strategy, capable of reducing the cytotoxic effects of venom phospholipase A2s from three different snake genera from different continents. This highlights the potential of utilizing monoclonal antibodies to develop more effective, safer, and globally accessible polyvalent antivenoms that can be widely used to treat snakebite envenoming.

Museum DNA reveals a new, potentially extinct species of rinkhals (Serpentes: Elapidae: Hemachatus) from the Eastern Highlands of Zimbabwe.

Genetic information plays a pivotal role in species recognition and delimitation, but rare or extinct animals can be difficult to obtain genetic samples from. While natural history wet collections have proven invaluable in the description of novel species, the use of these historical samples in genetic studies has been greatly impeded by DNA degradation, especially because of formalin-fixation prior to preservation. Here, we use recently developed museum genomics approaches to determine the status of an isolated population of the elapid snake genus Hemachatus from Zimbabwe. We used multiple digestion phases followed by single strand sequencing library construction and hybridisation capture to obtain 12S and 16S rDNA sequences from a poorly preserved tissue sample of this population. Phylogenetic and morphological analyses in an integrated taxonomic framework demonstrate that the Zimbabwean rinkhals population represents an old and highly distinct lineage, which we describe as a new species, Hemachatus nyangensis sp. nov. Our phylogenetic dating analysis is compatible with venom spitting having evolved in response to the threat posed by early hominins, although more data are required for a robust test of this hypothesis. This description demonstrates the power of museum genomics in revealing rare or even extinct species: Hemachatus from Zimbabwe are only known from a small area of the Eastern Highlands known for high endemism. No living specimens have been seen since the 1980s, most likely due to dramatic land-use changes in the Eastern Highlands, suggesting that the species could be extinct. In view of its recognition as a highly distinct lineage, urgent action is required to determine whether any populations survive, and to safeguard remaining habitat.

Phylogeny and morphology of the Australian snake genus Neelaps Günther, 1863 (Squamata: Elapidae), with resurrection of Narophis Worrell, 1961

Recent phylogenetic studies have shown that the affinities of the two currently recognised species of Neelaps Günther, 1863, Neelaps bimaculatus (Duméril, Bibron & Duméril, 1854) and Neelaps calonotos (Duméril, Bibron & Duméril, 1854), are unresolved. Here we provide an expanded molecular phylogeny and new morphology data to clarify generic boundaries. We did not find support for monophyly of Neelaps, confirming previous evidence. As a consequence, we allocate bimaculatus to the available synonym Narophis Worrell, 1961 and restrict calonotos to Neelaps, forming two monotypic genera. We redescribe both species under this revised classification. Neelaps calonotos adds to the list of endemic monotypic vertebrates in southwestern Western Australia, recognised globally as a biodiversity hotspot, and we comment on the name spelling, type specimens and conservation status of this distinctive species.

Hiding in the mists: molecular phylogenetic position and description of a new genus and species of snake (Dipsadidae: Xenodontinae) from the remote cloud forest of the Lost World

AbstractPantepui s.l. is a remote, biodiverse region of ~400 000 km2 containing at least five endemic reptile genera and a number of ancient vertebrate lineages. Here, we describe an additional endemic snake genus and species, Paikwaophis krukigen. nov., sp. nov. (Dipsadidae: Xenodontinae), recently collected in the Pantepui cloud forest that sits at the base of the steep cliffs of Roraima-tepui and Wei-Assipu-tepui (table mountains of the Eastern Tepui Chain) in Guyana, South America. Multilocus molecular data strongly support Paikwaophisgen. nov. to be most closely related to Xenopholis Peters, 1869, although both genera are strikingly different morphologically. Osteological and other phenotypic data suggest that Paikwaophis is semi-fossorial; its diet includes minute lizards. Paikwaophis is currently the only known Pantepui endemic snake genus. The immature female holotype is the only known specimen.

Synophis lasallei (NICÉFORO-MARIA, 1950) (SQUAMATA: COLUBRIDAE): NEW RECORD AND FILLING A DISTRIBUTION GAP IN THE CORDILLERA ORIENTAL OF COLOMBIA

Synophis is a genus of neotropical snakes distributed in Colombia, Ecuador, and Perú that remains poorly studied due to the cryptic habits of the species. S. lasallei is a small snake with disperse records on both slopes of the Cordillera Oriental in Colombia and recently has been found in the Cordillera Central. During a herpetology survey conducted in the western slope of the Cordillera Oriental, department of Huila, Colombia, I found an individual of S. lasallei inside a rotten log and the individual was preserved. This record fills a geographic gap of 401 km in the distribution of the species along the western slope of the aforementioned Cordillera. According to this report this species might be distributed along the entire extension of the Cordillera Oriental and Central but has not been extensively reported because it cryptic habits. Moreover, this report contributes to a better comprehension on the distribution of one little known snake.

On the taxonomy of Uropeltis petersi (Beddome, 1878) (Serpentes: Uropeltidae) and description of a new, closely related species from the Western Ghats of India.

A new species of the uropeltid snake genus Uropeltis Cuvier, 1829 is described from the environs of Munnar in the Anamalai hils of the Western Ghats of peninsular India. Uropeltis tricuspida sp. nov. superficially resembles the poorly known and closely related U. petersi, but differs from that species in having more ventral and subcaudal scales, and a tri- rather than bicuspid posterior tip to the terminal scute.

A NEW SPECIES OF WATER SNAKE GENUS HYPSISCOPUS (SERPENTES: HOMALOPSIDAE) FROM SULAWESI, INDONESIA

We describe a new species of water snake genus Hypsiscopus that was formerly placed in the genus Enhydris from Towuti Lake, South Sulawesi, based on six specimens collected in 2003 and a specimen collected in 2019. The new species has several significant differences from other species in the genus Hypsiscopus (H. matannensis, H. plumbea, and H. murphyi) in possessing laterally compressed tail, higher number of scale rows in mid body, higher number of ventral scales, lower number of subcaudal scales, and distinct color pattern. The new species is likely distributed only in the Towuti Lake, and has higher level endemicity compared to H. matannensis. Further studies on the population and distribution are needed to evaluate its conservation status.

First potential occurrence of the large aquatic snake Pterosphenus (Serpentes, Palaeophiidae) from Nigeria, with further documentation of Pterosphenus schweinfurthi from Egypt

Pterosphenus was a genus of giant aquatic snakes distributed across North and South America, Asia and Africa. In Africa, the known occurrences of the genus are scarce, comprising isolated vertebrae and ribs from Egypt, Libya, Morocco and Angola. Here, a trunk vertebra from the middle Eocene Ameki Formation of Ameki in Nigeria is tentatively referred to Pterosphenus. For comparative purposes, multiple previously undocumented trunk vertebrae from the upper Eocene of Fayum in Egypt are also illustrated—these pertain to Pterosphenus schweinfurthi, the only named species of Pterosphenus currently recognized from Africa. The Ameki Formation vertebra is significantly smaller and likely represents an osteologically immature individual. This new find hints at a higher diversity of palaeophiids from Nigeria, which otherwise include Palaeophis africanus from the age-equivalent middle Eocene Oshosun Formation. Georgios L. Georgalis [georgalis@isez.pan.krakow.pl], Institute of Systematics and Evolution of Animals, Polish Academy of Sciences, Sławkowska 17, 31‑016 Kraków, Poland.

Genomics reveals broad hybridization in deeply divergent Palearctic grass and water snakes (Natrix spp.)

Understanding speciation is one of the cornerstones of biological diversity research. Currently, speciation is often understood as a continuous process of divergence that continues until genetic or other incompatibilities minimize or prevent interbreeding. The Palearctic snake genus Natrix is an ideal group to study speciation, as it comprises taxa representing distinct stages of the speciation process, ranging from widely interbreeding parapatric taxa through parapatric species with very limited gene flow in narrow hybrid zones to widely sympatric species. To understand the evolution of reproductive isolation through time, we have sequenced the genomes of all five species within this genus and two additional subspecies. We used both long-read and short-read methods to sequence and de-novo-assemble two high-quality genomes (Natrix h. helvetica, Natrix n. natrix) to their 1.7 Gb length with a contig N50 of 4.6 Mbp and 1.5 Mbp, respectively, and used these as references to assemble the remaining short-read-based genomes. Our phylogenomic analyses yielded a well-supported dated phylogeny and evidence for a surprisingly complex history of interspecific gene flow, including between widely sympatric species. Furthermore, evidence for gene flow was also found for currently allopatric species pairs. Genetic exchange among these well-defined, distinct, and several million-year-old reptile species emphasizes that speciation and maintenance of species distinctness can occur despite continued genetic exchange.

Systematics of Trimeresurus popeiorum Smith, 1937 with a revised molecular phylogeny of Asian pitvipers of the genus Trimeresurus Lacépède, 1804 sensu lato

The pit viper snake genus Trimeresurus Lacépède, 1804 sensu lato, is a diverse group of nocturnal serpents comprising over 61 species. The genus is morphologically heterogeneous and has been divided into several subgenera. We present an updated phylogeny of Asian pitvipers and propose a revised classification. Additionally, we revise the taxonomy of T. popeiorum Smith, 1937 and propose taxonomic changes with support from molecular and morphological data. We restrict T. popeiorumsensu stricto to northeastern India, Bangladesh, southern China, and northern Myanmar; populations beyond these areas require further assessment. We also synonymize T. yingjiangensisChen et al., 2019 with T. popeiorum based on overlapping morphological characters, molecular data, and distribution. The findings shed new light on the taxonomy of T. popeiorum, warranting the need for assessing the population of T. popeiorum from southeast Asia.

Sound garden: How snakes respond to airborne and groundborne sounds.

Evidence suggests that snakes can hear, but how snakes naturally respond to sound is still unclear. We conducted 304 controlled experiment trials on 19 snakes across five genera in a sound-proof room (4.9 x 4.9 m) at 27ºC, observing the effects of three sounds on individual snake behavior, compared to controls. We quantified eight snake behaviors (body movement, body freezing, head-flicks, tongue-flicks, hissing, periscoping, head fixation, lower jaw drop) in response to three sounds, which were filtered pink-noise within the following frequency ranges: 0-150Hz (sound 1, which produced ground vibrations, as measured by an accelerometer), 150-300Hz (sound 2, which did not produced ground vibrations), 300-450Hz (sound 3, which did not produced ground vibrations). All snake responses were strongly genus dependent. Only one genus (Aspidites, Woma Pythons) significantly increased their probability of movement in response to sound, but three other genera (Acanthophis (Death Adders), Oxyuranus (Taipans), and Pseudonaja (Brown Snakes)) were more likely to move away from sound, signaling potential avoidance behavior. Taipans significantly increased their likelihood of displaying defensive and cautious behaviors in response to sound, but three of the five genera exhibited significantly different types of behaviors in sound trials compared to the control. Our results highlight potential heritable behavioral responses of snakes to sound, clustered within genera. Our study illustrates the behavioral variability among different snake genera, and across sound frequencies, which contributes to our limited understanding of hearing and behavior in snakes.

Afoxolaner (NexGard®) in pet snakes for the treatment and control of Ophionyssus natricis (Mesostigmata: Macronyssidae)

BackgroundOphionyssus natricis is the main species of mite that infests captive reptiles. High infestations may result in the host experiencing general discomfort and deleterious effects, even death. Moreover, O. natricis is an important vector of reptile vector-borne diseases and is considered to be the putative vector of the Reptarenavirus, the causal agent of the inclusion body disease. Despite the cosmopolitan distribution of O. natricis in captive reptiles, treatment options are limited. The aim of the present study was to assess the efficacy of afoxolaner (NexGard®; Boehringer Ingelheim, Ingelheim, Germany) in heavily infested, privately owned snakes, evaluate the prevalence of mites and drug availability in the plasma of treated snakes (pharmacokinetics) and perform a clinical examination of animals.MethodsThe study was conducted in two snake breeding facilities, where many snakes were infested with mites. Each animal was clinically examined and weighed, and mite infestations were assessed on the animals and in their enclosures (environment). Animals were treated with a dose of 2.5 mg afoxolaner per kilogram body weight (2.5 mg/kg) administered orally. All animals were examined pre-treatment (T0) and at various time points post-treatment (T1, 6 h; T2, 24 h; T3, 14 days; T4, 28 days). The collected mites were morphologically identified at the species level and the species identity also confirmed molecularly.ResultsOverall, 81 snakes from the two participating facilities (i.e. 70 from site 1 and 11 from site 2) were screened, and 31 (38.3%) snakes were found to have at least one mite. All mites were identified morphologically and molecularly as O. natricis. Lampropeltis was the genus of snakes with highest number of infested individuals. Mites were found to be alive on snakes at T1, but at T2 only dead mites were observed, and at T3 and T4 mites were no longer present on the animals or in their environment. No side effects were observed in the treated snakes.ConclusionsA single oral administration of afoxolaner at 2.5 mg/kg was a safe treatment for snakes and 100% effective for the eradication of natural O. natricis infestation without the need to treat the environment of the snake.Graphical

Clinical characteristics and use of antibiotics in a group of patients with snake bites in Colombia.

Millions of snake bites occur worldwide each year. Clinical practice guidelines generally do not recommend the use of prophylactic antibiotics. To determine the sociodemographic, clinical, and pharmacological variables and the use of antibiotics in a group of patients with snake bites in Colombia. A retrospective cross-sectional study was carried out. Patients affiliated with a Colombian health insurer who presented with snake bites between 2015 and 2022 were included. The cases were identified from the National Public Health Surveillance System. Sociodemographic, clinical and pharmacological variables were identified. Descriptive and bivariate analyses were performed. A total of 643 patients were analyzed, with a median age of 30.8 years, and 74.7% were men. The most frequently identified genus of snake was Bothrops (88.8%), and most incidents were classified as mild ophidian accidents (61.6%). A total of 59.7% of patients received snake antivenom. A total of 13.8% and 2.2% of the patients had cellulitis or abscesses, respectively. A total of 63.5% received antibiotics (50.6% for prophylaxis and 12.9% for treatment), especially cephalexin (25.9%), and most of the antibiotic management was considered inappropriate (91.7%). Most patients with snake bites received antibiotics, especially for prophylactic purposes, a clinical behavior that goes against current evidence. The use of antibiotics with an unsuitable spectrum for the microorganisms that are usually found in the wounds of these patients is frequent. The development of local clinical practice guidelines is required to help reduce the overprescription of antibiotics, as the excessive use of antimicrobials is the main determinant of antimicrobial resistance.