Envenomation by a common green racer (Chlorosoma viridissimum) in the Brazilian Amazon: A report of three cases.

Envenomations by the common green racer (Chlorosoma viridissimum) are seldom reported in the literature. Herein, we report three cases caused by the same specimen of C. viridissimum in three different victims in the Brazilian Amazon. In all cases, the victims were either a biologist or biology students that were handling the animal and were bitten in their upper limbs. The victims showed only local symptoms, such as edema, tooth marks, pain, erythema, ecchymoses and bleeding. One of the patients presented extensive ecchymosis. Two patients sought medical care, but were only treated for local manifestations and evolved without complications. Chlorosoma viridissimum is capable of provoking mild to moderate signs and symptoms.

Extinction debt and functional traits mediate community saturation over large spatiotemporal scales.

Determining if ecological communities are saturated (have a limit to the number of species they can support) has important implications for understanding community assembly, species invasions, and climate change. However, previous studies have generally been limited to short time frames that overlook extinction debt and have not explicitly considered how functional trait diversity may mediate patterns of community saturation. Here, we combine data from biodiversity surveys with functional and phylogenetic data to explore if the colonisation events after the Great American Biotic Interchange (closure of the Panamanian Isthmus) resulted in increases in species richness of communities of the snake family Dipsadidae. We determined the number and the direction of dispersal events between Central and South America by estimating ancestral areas based on a Bayesian time-calibrated phylogenetic analysis. We then evaluated whether variation in community saturation was mediated by the functional similarity of six traits for the resident and colonizing snakes and/or local environmental conditions. We found that colonised communities did not support more species than those that were not colonised. Moreover, we did not find an association between the functional diversity across sites and whether they were colonised by members from the lineages dispersing across the Isthmus or not. Instead, variation in species richness was predicted best by covariates such as time since colonisation and local environment. Taken together, our results suggest that snake communities of the Dipsadidae across the neotropics are saturated. Moreover, our research highlights two important factors to consider in studies of community saturation: extinction debt and the functional differences and similarities in species' ecological roles.

Determinar si las comunidades ecológicas están saturadas (si tienen un límite en el número de especies que pueden albergar) tiene importantes implicaciones para entender el ensamblaje de comunidades, las invasiones de especies y el cambio climático. Sin embargo, los estudios previos en esta área se han limitado generalmente a marcos temporales cortos, ignorando el concepto de deuda de extinción y no considerando explícitamente cómo la diversidad de rasgos funcionales puede mediar en los patrones de saturación de las comunidades. En este trabajo combinamos datos publicados de muestreos de campo con datos funcionales y filogenéticos para explorar si los eventos de colonización después del Gran Intercambio Biótico Americano (ocurrido con el cierre del istmo de Panamá) resultaron en aumentos en la riqueza de especies de las comunidades de la familia de serpientes Dipsadidae. Determinamos el número y la dirección de los eventos de dispersión entre América Central y América del Sur mediante la estimación de áreas ancestrales basada en un análisis filogenético Bayesiano calibrado en el tiempo. Luego evaluamos si la variación en la saturación de las comunidades estaba mediada por la similitud funcional de seis rasgos para las serpientes residentes y colonizadoras y/o por las condiciones ambientales locales. Encontramos que las comunidades colonizadas no contienen más especies que aquellas que no fueron colonizadas. Además, no encontramos ninguna relación entre la diversidad funcional de los sitios considerados y el hecho de que estuvieran colonizados o no por miembros de los linajes que se dispersaron a través del Istmo. En cambio, la variación en la riqueza de especies se predijo mejor por covariantes como el tiempo transcurrido desde la colonización y el clima local. En conjunto, nuestros resultados sugieren que las comunidades de Dipsadidae a lo largo del neotrópico están saturadas. Además, nuestra investigación destaca dos factores importantes a considerar en los estudios de saturación de comunidades: la existencia de una deuda de extinción y las diferencias y similitudes funcionales en los papeles ecológicos de las especies.

Independent Recruitment of Different Types of Phospholipases A2 to the Venoms of Caenophidian Snakes: The Rise of PLA2-IIE within Pseudoboini (Dipsadidae).

Snake venoms harbor a wide and diverse array of enzymatic and nonenzymatic toxic components, allowing them to exert myriad effects on their prey. However, they appear to trend toward a few optimal compositional scaffolds, dominated by four major toxin classes: SVMPs, SVSPs, 3FTxs, and PLA2s. Nevertheless, the latter appears to be restricted to vipers and elapids, as it has never been reported as a major venom component in rear-fanged species. Here, by investigating the original transcriptomes from 19 species distributed in eight genera from the Pseudoboini tribe (Dipsadidae: Xenodontinae) and screening among seven additional tribes of Dipsadidae and three additional families of advanced snakes, we discovered that a novel type of venom PLA2, resembling a PLA2-IIE, has been recruited to the venom of some species of the Pseudoboini tribe, where it is a major component. Proteomic and functional analyses of these venoms further indicate that these PLA2s play a relevant role in the venoms from this tribe. Moreover, we reconstructed the phylogeny of PLA2s across different snake groups and show that different types of these toxins have been recruited in at least five independent events in caenophidian snakes. Additionally, we present the first compositional profiling of Pseudoboini venoms. Our results demonstrate how relevant phenotypic traits are convergently recruited by different means and from homologous and nonhomologous genes in phylogenetically and ecologically divergent snake groups, possibly optimizing venom composition to overcome diverse adaptative landscapes.

Hábitos alimentares das tribos da família Dipsadidae

Feeding habits are important for understanding the behavior of organisms in their respective habitats, and their interactions. Food habit is also an important factor for comparing diet and predation among individuals of the same taxonomic category, such as family, subfamily, tribe, genus, etc.Therefore, the aim of this work is to review and compile data from the literature on the feeding habits of snakes of five Dipsadidae tribes: Dipsadini, Elapomorphini, Philodryadini, Pseudoboini, and Xenodontini. Data on diet, predation, and feeding habits were searched, for understanding the traits of each tribe. The representatives of the tribe Dipsadini for example, have a diet of gastropods, slugs and snails, the tribe Elapomorphini has a specialized diet in ophiophagy, i.e., a diet based on other snakes, while the tribes Philodryadini and Pseudoboini both have a more generalist diet, it can be observed that small lizards and mammals are the most consumed in these two tribes, and the tribe Xenodontini specializes in preying on anurans. These results were obtained based on the food items described in the literature, such as amphibians, birds, gastropods, lizards, mammals, fish, eggs and snakes, so in the present study will also be analyzed, what are the characteristics of specialization and generalization regarding the diets of each tribe.

O hábito alimentar, é importante para compreender comportamentos dos organismos em seus respectivos habitats e as suas interações. O hábito alimentar também é um fator importante para comparar dieta e predação entre indivíduos da mesma categoria taxonômica, como por exemplo, família, subfamília, tribo, gênero e etc. Por isso o intuito deste trabalho foi revisar e compilar dados da literatura em relação a hábitos alimentares de serpentes de cinco tribos da família Dipsadidae, sendo elas Dipsadini, Elapomorphini, Philodryadini, Pseudoboini e Xenodontini. Dados de dieta, predação e hábitos alimentares foram levantados para compreender as tendências e padrões de cada tribo. Os representantes da tribo Dipsadini por exemplo, tem a sua dieta em gastrópodes lesmas e caramujo, na tribo Elapomorphini tem sua dieta especializada em ofiofagia ou seja, dieta a base de outras serpentes, já as tribos Philodryadini e Pseudoboini ambos possuem uma alimentação mais generalista, posso pode se observar que pequenos lagartos e mamíferos são os mais consumidos nestas duas tribos, e a tribo Xenodontini é especialista em predar anuros. Esses resultados foram obtidos com base em itens alimentares descrito na literatura como por exemplo, anfíbios, aves, gastrópodes, lagartos, mamíferos, peixes, ovos e serpentes, portanto no presente estudo será analisado também, quais características de especialização e generalização em relação a dietas de cada tribo.

Independent Recruitment of Different Types of Phospholipases A2 to the Venoms of Caenophidian Snakes: The Rise of PLA2-IIE within Pseudoboini (Dipsadidae)

Snake venoms harbor a wide and diverse array of enzymatic and nonenzymatic toxic components, allowing them to exert myriad effects on their prey. However, they appear to trend toward a few optimal compositional scaffolds, dominated by four major toxin classes: SVMPs, SVSPs, 3FTxs, and PLA2s. Nevertheless, the latter appears to be restricted to vipers and elapids, as it has never been reported as a major venom component in rear-fanged species. Here, by investigating the original transcriptomes from 19 species distributed in eight genera from the Pseudoboini tribe (Dipsadidae: Xenodontinae) and screening among seven additional tribes of Dipsadidae and three additional families of advanced snakes, we discovered that a novel type of venom PLA2, resembling a PLA2-IIE, has been recruited to the venom of some species of the Pseudoboini tribe, where it is a major component. Proteomic and functional analyses of these venoms further indicate that these PLA2s play a relevant role in the venoms from this tribe. Moreover, we reconstructed the phylogeny of PLA2s across different snake groups and show that different types of these toxins have been recruited in at least five independent events in caenophidian snakes. Additionally, we present the first compositional profiling of Pseudoboini venoms. Our results demonstrate how relevant phenotypic traits are convergently recruited by different means and from homologous and nonhomologous genes in phylogenetically and ecologically divergent snake groups, possibly optimizing venom composition to overcome diverse adaptative landscapes.

Independent recruitment of different types of Phospholipases A2 to the venoms of Caenophidian snakes: the rise of PLA2-IIE within Pseudoboini (Dipsadidae)

Snake venoms harbor a wide and diverse array of enzymatic and nonenzymatic toxic components, allowing them to exert myriad effects on their prey. However, they appear to trend toward a few optimal compositional scaffolds, dominated by four major toxin classes: SVMPs, SVSPs, 3FTxs, and PLA2s. Nevertheless, the latter appears to be restricted to vipers and elapids, as it has never been reported as a major venom component in rear-fanged species. Here, by investigating the original transcriptomes from 19 species distributed in eight genera from the Pseudoboini tribe (Dipsadidae: Xenodontinae) and screening among seven additional tribes of Dipsadidae and three additional families of advanced snakes, we discovered that a novel type of venom PLA2, resembling a PLA2-IIE, has been recruited to the venom of some species of the Pseudoboini tribe, where it is a major component. Proteomic and functional analyses of these venoms further indicate that these PLA2s play a relevant role in the venoms from this tribe. Moreover, we reconstructed the phylogeny of PLA2s across different snake groups and show that different types of these toxins have been recruited in at least five independent events in caenophidian snakes. Additionally, we present the first compositional profiling of Pseudoboini venoms. Our results demonstrate how relevant phenotypic traits are convergently recruited by different means and from homologous and nonhomologous genes in phylogenetically and ecologically divergent snake groups, possibly optimizing venom composition to overcome diverse adaptative landscapes.

Phylogenetic and morphological evidence reveals the association between diet and the evolution of the venom delivery system in Neotropical goo-eating snakes

Advanced endoglyptodont snakes share a complex but homologous venom delivery system associated with the upperjaw and its dentition. Recently, a remarkable novel lower jaw venom delivery system was described for the Neotropicaldipsadine radiation of goo-eating snakes. While most dipsadines are opistoglyphous and exhibit large, mainly serousvenom glands associated with the upper jaw and supralabial glands, goo-eating dipsadine snakes are aglyphous and lackserous upper labial venom glands. Here, we provide new morphological and histological information on the oral glandsand maxillary dentition of representatives of the major lineages of dipsadines that help trace the evolutionary steps thatshaped the venom delivery system of dipsadines. We performed a maximum likelihood analysis on a molecular datasetthat includes 443 terminals and seven loci. Our results show that goo-eating dipsadines form a monophyletic assemblagethat includes the genusAdelphicosfor the first time, along withGeophis,Atractus,Ninia,Chersodromus,Tropidodipsas,Sibon, andDipsas. We also provide the first evidence of a complete shift from an upper jaw to a lower jaw venomdelivery system associated with their specialized feeding behaviour. Unlike other dipsadines who exhibit typicalendoglyptodont anteroposteriorly ridged posterior maxillary teeth, goo-eating dipsadines have uniform lateromediallyridged teeth throughout their maxilla. Our results indicate that the loss of the endoglyptodont venom delivery systemoccurred in the most recent common ancestor of goo-eating dipsadines, probably resulting from the loss of theembryonic posterior maxillary lamina responsible for the development of the venom delivery system.

Bites by Xenodon merremii (Wagler, 1824) and Xenodon neuwiedii (Günther, 1863) (Dipsadidae: Xenodontini) in São Paulo, Brazil: a retrospective observational study of 163 cases.

Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about their medical significance. Here, we describe the clinical, epidemiological, and biological aspects of bites by two colubroid species. We retrospectively analyzed cases of Xenodon merremii and Xenodon neuwiedii bites in which the offending snake was clearly identified. Analyses included variables related to the snake and the patient, including demographic data, clinical findings, and treatments. Of the 163 cases, 123 were bites by X. merremii and 40 by X. neuwiedii. Most bites occurred in spring and summer, predominantly during the daytime. Most offending snakes were female. Bites by X. merremii juveniles were more frequent in autumn than in other seasons, whereas those by X. neuwiedii adults were in the summer. Hands and feet were the most frequently affected regions, with no significant difference between upper and lower limbs bitten by either X. merremii or X. neuwiedii. The main clinical findings were pain, transitory bleeding, erythema, and local edema. Local edema was proportionally more frequent with X. neuwiedii bites than with X. merremii bites. No patient had extensive edema or systemic envenomation. A significant association between the snout-vent-length and transitory bleeding in bites by X. merremii, but not in those by X. neuwiedii, was identified. Whole blood clotting tests were normal in all tested patients (62 cases). Sixteen patients were incorrectly treated with anti-Bothrops antivenom. In conclusion, most accidents caused by X. merremii and X. neuwiedii present mild local symptomatology. These snakes can be mistaken for lance-headed vipers, and some bites present symptoms that resemble mild bites by Bothrops sp. Physicians should be aware of X. merremii and X. neuwiedii bites to avoid unnecessary patient distress and overprescription of antivenom.

Bites by Philodryas olfersii (Lichtenstein, 1823) and Philodryas aestiva (Duméril, Bibron and Duméril, 1854) (serpentes, dipsadidae) in São Paulo, Brazil: A retrospective observational study of 155 cases.

Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about the medical significance of the majority these species. Herein, we described bites by two green racer species of colubroid snakes, with respect to clinical, epidemiological, and biological features. We retrospectively analyzed proven cases of Philodryas olfersii and Philodryas aestiva bites. Only cases in which the causative animal was brought and identified by an expert were included. Analysis included variables related to the snake, patient demographics, clinical findings, whole blood clotting time (WBCT20), and treatments. Total 155 medical records were analyzed, of which 141 and 14 patients each were bitten by P. olfersii and P. aestiva, respectively. Most bites occurred in spring and summer seasons, predominantly during daytime. Most snakes were female and adult. Bites by P. olfersii adults were more frequent in summer (p < 0.001) and spring (p < 0.001). The hands were most frequently bitten by P. olfersii (59.6%), while the feet and legs (71.4%) were most bitten by P. aestiva. The most common local signs or symptoms observed were pain, edema, erythema, and transitory local bleeding. Severe pain, extensive edema, ecchymosis, and paresthesia were present only in patients bitten by P. olfersii. Significant association was observed between local bleeding and adult snakes (p = 0.019), as well as between the snout-vent-length and pain (p = 0.018), extensive edema (p = 0.024), and erythema (p = 0.047). WBCT20 was normal in the 35 cases in which it was available. Two patients were wrongly treated with anti-Bothrops antivenom. These results indicated that most accidents caused by P. olfersii and P. aestiva present mild local symptomatology. Some bites of P. olfersii bites may present local symptoms, resembling bites by Bothrops-like snakes. Physicians should be informed about these kinds of accidents, to avoid unnecessary distress to the patient and over prescription of antivenom.

Bites by Xenodon merremii (Wagler, 1824) and Xenodon neuwiedii (Günther, 1863) (Dipsadidae: Xenodontini) in São Paulo, Brazil: a retrospective observational study of 163 cases

Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about their medical significance. Here, we describe the clinical, epidemiological, and biological aspects of bites by two colubroid species. We retrospectively analyzed cases of Xenodon merremii and Xenodon neuwiedii bites in which the offending snake was clearly identified. Analyses included variables related to the snake and the patient, including demographic data, clinical findings, and treatments. Of the 163 cases, 123 were bites by X. merremii and 40 by X. neuwiedii. Most bites occurred in spring and summer, predominantly during the daytime. Most offending snakes were female. Bites by X. merremii juveniles were more frequent in autumn than in other seasons, whereas those by X. neuwiedii adults were in the summer. Hands and feet were the most frequently affected regions, with no significant difference between upper and lower limbs bitten by either X. merremii or X. neuwiedii. The main clinical findings were pain, transitory bleeding, erythema, and local edema. Local edema was proportionally more frequent with X. neuwiedii bites than with X. merremii bites. No patient had extensive edema or systemic envenomation. A significant association between the snout-vent-length and transitory bleeding in bites by X. merremii, but not in those by X. neuwiedii, was identified. Whole blood clotting tests were normal in all tested patients (62 cases). Sixteen patients were incorrectly treated with anti-Bothrops antivenom. In conclusion, most accidents caused by X. merremii and X. neuwiedii present mild local symptomatology. These snakes can be mistaken for lance-headed vipers, and some bites present symptoms that resemble mild bites by Bothrops sp. Physicians should be aware of X. merremii and X. neuwiedii bites to avoid unnecessary patient distress and overprescription of antivenom.

Bites by Philodryas olfersii (Lichtenstein, 1823) and Philodryas aestiva (Duméril, Bibron and Duméril, 1854) (serpentes, dipsadidae) in São Paulo, Brazil: a retrospective observational study of 155 cases

Despite the biological relevance and abundance of non-front-fanged colubroid snakes, little is known about the medical significance of the majority these species. Herein, we described bites by two green racer species of colubroid snakes, with respect to clinical, epidemiological, and biological features. We retrospectively analyzed proven cases of Philodryas olfersii and Philodryas aestiva bites. Only cases in which the causative animal was brought and identified by an expert were included. Analysis included variables related to the snake, patient demographics, clinical findings, whole blood clotting time (WBCT20), and treatments. Total 155 medical records were analyzed, of which 141 and 14 patients each were bitten by P. olfersii and P. aestiva, respectively. Most bites occurred in spring and summer seasons, predominantly during daytime. Most snakes were female and adult. Bites by P. olfersii adults were more frequent in summer (p < 0.001) and spring (p < 0.001). The hands were most frequently bitten by P. olfersii (59.6%), while the feet and legs (71.4%) were most bitten by P. aestiva. The most common local signs or symptoms observed were pain, edema, erythema, and transitory local bleeding. Severe pain, extensive edema, ecchymosis, and paresthesia were present only in patients bitten by P. olfersii. Significant association was observed between local bleeding and adult snakes (p = 0.019), as well as between the snout-vent-length and pain (p = 0.018), extensive edema (p = 0.024), and erythema (p = 0.047). WBCT20 was normal in the 35 cases in which it was available. Two patients were wrongly treated with anti-Bothrops antivenom. These results indicated that most accidents caused by P. olfersii and P. aestiva present mild local symptomatology. Some bites of P. olfersii bites may present local symptoms, resembling bites by Bothrops-like snakes. Physicians should be informed about these kinds of accidents, to avoid unnecessary distress to the patient and over prescription of antivenom.

Patagonin-CRISP: antimicrobial activity and source of antimicrobial molecules in duvernoy's gland secretion (Philodryas patagoniensis Snake)

Snake venom contains a variety of toxins with a range of biological activity, among these toxins cysteine-rich secreted proteins (CRISPs) can be found. The proteins of this family have masses of 20–30 kDa and display homologous amino acid sequences containing 16 cysteine residues, forming eight disulfide bonds. Some of these proteins have been explored, characterized, and described in terms of their activity; however, little is known about their range of activities. A search for new antimicrobial molecules is ongoing, as the number of microbial strains resistant to available antibiotics is increasing. We identified antimicrobial activity in the secretion of Duvernoy's gland of the rear-fanged Philodryas patagoniensis. Fractions of this venom were subjected to reverse-phase high performance liquid chromatography and analyzed to determine their antimicrobial activity with a liquid broth inhibition assay. One of the fractions presented activity against a Gram-negative bacterium and a filamentous fungus. This fraction was analyzed with LC-MS/MS, and a protein of 24,848.8 Da was identified. Database searches allowed us to identify it as a CRISP due to the presence of some unique fragments in the molecule. We called it patagonin-CRISP, as the same protein in the venom of P. patagoniensis had previously been characterized as having a different biological activity. Patagonin-CRISP presented activity at very low concentrations and showed no cytotoxic activity. This is the first time that antimicrobial activity has been identified for P. patagoniensis venom or for a CRISP family protein.

Patagonin-CRISP: Antimicrobial Activity and Source of Antimicrobial Molecules in Duvernoy's Gland Secretion (Philodryas patagoniensis Snake).

Snake venom contains a variety of toxins with a range of biological activity, among these toxins cysteine-rich secreted proteins (CRISPs) can be found. The proteins of this family have masses of 20-30 kDa and display homologous amino acid sequences containing 16 cysteine residues, forming eight disulfide bonds. Some of these proteins have been explored, characterized, and described in terms of their activity; however, little is known about their range of activities. A search for new antimicrobial molecules is ongoing, as the number of microbial strains resistant to available antibiotics is increasing. We identified antimicrobial activity in the secretion of Duvernoy's gland of the rear-fanged Philodryas patagoniensis. Fractions of this venom were subjected to reverse-phase high performance liquid chromatography and analyzed to determine their antimicrobial activity with a liquid broth inhibition assay. One of the fractions presented activity against a Gram-negative bacterium and a filamentous fungus. This fraction was analyzed with LC-MS/MS, and a protein of 24,848.8 Da was identified. Database searches allowed us to identify it as a CRISP due to the presence of some unique fragments in the molecule. We called it patagonin-CRISP, as the same protein in the venom of P. patagoniensis had previously been characterized as having a different biological activity. Patagonin-CRISP presented activity at very low concentrations and showed no cytotoxic activity. This is the first time that antimicrobial activity has been identified for P. patagoniensis venom or for a CRISP family protein.

Bites by Tomodon dorsatus (serpentes, dipsadidae): Clinical and epidemiological study of 86 cases.

A total of 86 proven cases of Tomodon dorsatus bites admitted to Hospital Vital Brazil (HVB) of Butantan Institute, in São Paulo, Brazil, between 1945 and 2018, were retrospectively analyzed. The cases included were those in which the snake was brought to HVB and was correctly identified. Of the 86 cases of snake bites, it was possible to describe the sex of the snake in 52 cases; 31 (59.6%) snakes were male. Only 52 snakes out of 86 could be studied because of their preservation status. The length of snakes (snout-vent length) ranged from 180 to 770 mm. Of the 86 snakes, 72 could be distinguished as adults (n = 63, 87.5%) or juveniles (n = 9, 12.5%). Most bites occurred in the spring and summer seasons (n = 57, 66.3%) and during warmer periods of the day (n = 61, 72.6%), between 9 a.m. and 3 p.m. The mean (±standard deviation) age of the victims was 26.9 ±â€¯17.2 years, and 60 (69.8%) were men. Approximately 90% of the patients sought medical care within 6 h after the bite. Both upper (n = 45, 52.3%) and lower (n = 37, 43.0%) limbs were the most frequently bitten, particularly the feet and hands (n = 54, 62.8%). The local clinical manifestations were pain (n = 55, 64.0%), transitory bleeding (n = 23, 26.7%), erythema (n = 22, 25.6%), edema (n = 14, 16.3%), paresthesia (n = 9, 10.5%), and ecchymosis (n = 3, 3.5%). Only 10 (11.6%) patients reported non-specific systemic symptoms characterized by transient dizziness or mild headache, and 21 (24.4%) patients showed no evidence of envenomation. A 20 min whole blood clotting test was performed in 31 (36.0%) patients on admission and all of them had coagulable blood. Supportive treatment was offered to 38 (44.2%) patients, namely, antiseptic (n = 20, 23.3%), antihistamines (n = 12, 14.0%), and analgesics (n = 9, 10.5%). Four (4.7%) patients were inappropriately treated with Bothrops antivenom before their admission to HVB. No sequelae or relevant complications were observed in patients, and the prognosis was benign. Therefore, although T. dorsatus bites can cause mild local symptomatology, it is important that health professionals know how to make the correct diagnosis to avoid unnecessary use of antivenom.

On the second specimen of Atractus alytogrammus (Serpentes: Dipsadidae), with description of its unusual hemipenial morphology.

The semi-fossorial snakes of the genus Atractus Wagler 1828 are widely distributed throughout South America, ranging from Panama to northeastern Argentina at elevations from sea level to 4500 m (Passos et al. 2013a). Atractus currently comprises 150 species that inhabiting several types of tropical habitats, being the most diverse genus of snakes in the world (Passos et al. 2018). Colombia harbours the most species richness of the genus with about 42 currently recognized species, representing about 1/3 of generic diversity (Uetz et al. 2018). Köhler Kieckbusch (2014) recently has named Atractus alytogrammus based on an individual collected by Federico Meden more than fifty years ago near the municipality of San José de Guaviare (2°33'55''N, 72°38'19''W). The second known specimen of A. alytogrammus was found by A.F. Aponte (male, ICN-R-13018) hidden under a pile of palm leaves (3°00'05"N, 72°13'9.9"W; 209 m above sea level) at 7:58 am on February 02 2016 in the oil palm plantations of POLIGROW Colombia Ltda, municipality of Mapiripán, department of Meta, Colombia. This region is located in the Orinoquia-Amazonia ecotone 82 Km (airline) northeast from the type-locality (Fig. 1). I report herein the unknown color in life (Fig. 2), change of shades after preservation (Fig. 3B-D) and hemipenial morphology (Fig. 4), besides amplifying the meristic and morphometric variability of this poorly known species (Table 1).

Bites by Tomodon dorsatus (serpentes, dipsadidae): clinical and epidemiological study of 86 cases

A total of 86 proven cases ofTomodon dorsatusbites admitted to Hospital Vital Brazil (HVB) of ButantanInstitute, in São Paulo, Brazil, between 1945 and 2018, were retrospectively analyzed. The cases included werethose in which the snake was brought to HVB and was correctly identified. Of the 86 cases of snake bites, it waspossible to describe the sex of the snake in 52 cases; 31 (59.6%) snakes were male. Only 52 snakes out of 86could be studied because of their preservation status. The length of snakes (snout–vent length) ranged from 180to 770 mm. Of the 86 snakes, 72 could be distinguished as adults (n = 63, 87.5%) or juveniles (n = 9, 12.5%).Most bites occurred in the spring and summer seasons (n = 57, 66.3%) and during warmer periods of the day(n = 61, 72.6%), between 9A.M. and 3P.M. The mean ( ± standard deviation) age of the victims was 26.9 ± 17.2 years, and 60 (69.8%) were men.Approximately 90% of the patients sought medical care within 6 h after the bite. Both upper (n = 45, 52.3%)and lower (n = 37, 43.0%) limbs were the most frequently bitten, particularly the feet and hands (n = 54,62.8%). The local clinical manifestations were pain (n = 55, 64.0%), transitory bleeding (n = 23, 26.7%), er-ythema (n = 22, 25.6%), edema (n = 14, 16.3%), paresthesia (n = 9, 10.5%), and ecchymosis (n = 3, 3.5%).Only 10 (11.6%) patients reported non-specific systemic symptoms characterized by transient dizziness or mildheadache, and 21 (24.4%) patients showed no evidence of envenomation. A 20 min whole blood clotting test wasperformed in 31 (36.0%) patients on admission and all of them had coagulable blood. Supportive treatment wasoffered to 38 (44.2%) patients, namely, antiseptic (n = 20, 23.3%), antihistamines (n = 12, 14.0%), and an-algesics (n = 9, 10.5%). Four (4.7%) patients were inappropriately treated withBothropsantivenom before theiradmission to HVB. No sequelae or relevant complications were observed in patients, and the prognosis wasbenign. Therefore, althoughT. dorsatusbites can cause mild local symptomatology, it is important that healthprofessionals know how to make the correct diagnosis to avoid unnecessary use of antivenom.

Non-venomous snakebites in the Western Brazilian Amazon

Abstract INTRODUCTION: In this study, we examined the clinical manifestations, laboratory evidence, and the circumstances of snakebites caused by non-venomous snakes, which were treated at the Regional Hospital of Juruá in Cruzeiro do Sul. METHODS: Data were collected through patient interviews, identification of the species that were taken to the hospital, and the clinical manifestations. RESULTS: Eight confirmed and four probable cases of non-venomous snakebites were recorded. CONCLUSIONS: The symptoms produced by the snakes Helicops angulatus and Philodryas viridissima, combined with their coloration can be confused with venomous snakes (Bothrops atrox and Bothrops bilineatus), thus resulting in incorrect bothropic snakebite diagnosis.

The taxonomic status of the "forgotten" Bolivian snakes, Atractus balzani Boulenger 1898 and Atractus maculatus (sensu Boulenger 1896) (Serpentes: Dipsadidae).

The genus Atractus Wagler 1828 comprises almost 150 currently recognized species of cryptozoic snakes widespread in the Neotropics, occurring from Panama to northeastern Argentina (Passos et al. 2016a). Despite the publication of the descriptions of several new species within the last decade, the taxonomy of the genus is unclear in some instances. This is mainly due to the fact that a number of poorly delimited taxa still exist (Passos et al. 2018). The most frequent problem faced by taxonomist working with the genus Atractus is the lack of specimens available for several species, most of them only still being known from their types, a situation that considerably weakens the definition of species boundaries between closely related taxa (Passos et al. 2010a, 2013). More importantly, many of the previously recognized species may represent aberrant individuals with unusual or abnormal scale counts, anomalous azygous or fused cephalic plates, infrequent polychromatic patterns, or any combination of these states (see Passos et al. 2016b). In the course of a thorough taxonomic review of the genus (Passos 2008; Passos et al. 2018), an effort has been made to examine all of the available types (including those apparently lost or misplaced in collections) and material of historical importance that was previously referred to the genus in the literature, and these were then compared to newer samples collected more recently. During the examination of the collections of the Natural History Museum of London and the Museo Civico di Storia Naturale of Genova, we found important specimens of Atractus from Bolivia. However, in order to better understand all the problems related to these old and "forgotten" Bolivian snakes, we need to examine their history.

Origin and hidden diversity within the poorly known Galápagos snake radiation (Serpentes: Dipsadidae)

Galápagos snakes are among the least studied terrestrial vertebrates of the Archipelago. Here, we provide a phylogenetic analysis and a time calibrated tree for the group, based on a sampling of the major populations known to occur in the Archipelago. Our study revealed the presence of two previously unknown species from Santiago and Rábida Islands, and one from Tortuga, Isabela, and Fernandina. We also recognize six additional species of Pseudalsophis in the Galápagos Archipelago (Pseudalsophis biserialis from San Cristobal, Floreana and adjacent islets; Pseudalsophis hoodensis from Española and adjacent islets; Pseudalsophis dorsalis from Santa Cruz, Baltra, Santa Fé, and adjacent islets; Pseudalsophis occidentalis from Fernandina, Isabela, and Tortuga; Pseudalsophis slevini from Pinzon, and Pseudalsophis steindachneri from Baltra, Santa Cruz and adjacent islets). Our time calibrated tree suggests that the genus Pseudalsophis colonized the Galápagos Archipelago through a single event of oceanic dispersion from the coast of South America that occurred at approximately between 6.9?Ma and 4.4?Ma, near the Miocene/Pliocene boundary.

A new species of earth snake (Dipsadidae, Geophis) from Mexico.

A new species of the Geophis dubius group is described from the mountains of the Sierra Zongolica in west-central Veracruz and the Sierra de Quimixtlán in central-east Puebla. The new species is most similar to Geophis duellmani and Geophis turbidus, which are endemic to the mountains of northern Oaxaca and the Sierra Madre Oriental of Puebla and Hidalgo, respectively. However, the new species differs from Geophis duellmani by the presence of postocular and supraocular scales and from Geophis turbidus by having a bicolor dorsum. With the description of the new species, the species number in the genus increases to 50 and to 12 in the Geophis dubius group. Additionally, a key to the species of the Geophis dubius group is provided.