Ecological correlates of cranial evolution in the megaradiation of dipsadine snakes.

BACKGROUND: Dipsadine snakes represent one of the most spectacular vertebrate radiations that have occurred in any continental setting, with over 800 species in South and Central America. Their species richness is paralleled by stunning ecological diversity, ranging from arboreal snail-eating and aquatic eel-eating specialists to terrestrial generalists. Despite the ecological importance of this clade, little is known about the extent to which ecological specialization shapes broader patterns of phenotypic diversity within the group. Here, we test how habitat use and diet have influenced morphological diversification in skull shape across 160 dipsadine species using micro-CT and 3-D geometric morphometrics, and we use a phylogenetic comparative approach to test the contributions of habitat use and diet composition to variation in skull shape among species. RESULTS: We demonstrate that while both habitat use and diet are significant predictors of shape in many regions of the skull, habitat use significantly predicts shape in a greater number of skull regions when compared to diet. We also find that across ecological groupings, fossorial and aquatic behaviors result in the strongest deviations in morphospace for several skull regions. We use simulations to address the robustness of our results and describe statistical anomalies that can arise from the application of phylogenetic generalized least squares to complex shape data. CONCLUSIONS: Both habitat and dietary ecology are significantly correlated with skull shape in dipsadines; the strongest relationships involved skull shape in snakes with aquatic and fossorial lifestyles. This association between skull morphology and multiple ecological axes is consistent with a classic model of adaptive radiation and suggests that ecological factors were an important component in driving morphological diversification in the dipsadine megaradiation.

Prevalencia de endoparásitos gastrointestinales y ectoparásitos en serpientes ex situ en Barranquilla, Colombia / Prevalence of gastrointestinal endoparasites and ectoparasites in ex situ snakes in Barranquilla, Colombia

RESUMEN Objetivo. Identificar la prevalencia de endoparásitos y ectoparásitos en serpientes ex situ en la Fundación Botánica y Zoológica de Barranquilla "Barranquilla Zoo". Materiales y métodos. Para esto se analizaron muestras de materia fecal y ectoparásitos de 2 colúbridos (Leptophis ahaetulla y Spilotes pullatus), 2 dipsadinos (Oxybelys aeneus y Thamnodynastes paraguanae) y 13 boidos (9 individuos de la especie Boa constrictor, 2 de Epicrates maurus y 2 de Eunectes murinus) utilizando los métodos de flotación en solución saturada de azúcar y observación directa. Resultados. Los resultados obtenidos mostraron que el 65% (11/17) de los animales evaluados fueron positivos a la presencia de parásitos, de los cuales el 91% (10/11) de los ejemplares pertenece a la familia Boidae presentando en su mayoría nematodos, mientras que en los dipsadinos se observaron principalmente protozoarios y los colúbridos resultaron negativos. Finamente como ectoparásitos se identificaron 2 especies de garrapatas (Amblyomma dissimile y Ornothodoros turicata) halladas en ejemplares de Boa constrictor, Epicrates maurus y Spilotes pullatus. Conclusiones. La identificación de las formas parasitarias en este trabajo representa una contribución para el conocimiento de los parásitos en serpientes ex situ en Colombia. Provee información para desarrollar medidas profilácticas y permite comparar los datos sobre las formas parasitarias encontradas con muestreos de estas especies en vida silvestre y bajo cuidados humanos.

ABSTRACT Objective. Identify the prevalence of internal and external parasites in ex situ snakes at the Fundación Botánica y Zoológica de Barranquilla "Barranquilla Zoo". Materials and methods. Stool samples and ectoparasites of 2 colubrids (Leptophis ahaetulla and Spilotes pullatus), 2 diapsids (Oxybelys aeneus and Thamnodynastes paraguanae) and 13 boids (9 individuals of Boa constrictor, 2 of Epicrates maurus and 2 Eunectes murinus) were analyzed using flotation method in saturated sugar solution and direct observation. Results. The results showed that 65% (11/17) of the population was positive to the presence of parasites. In relation to the positive specimens, 91% (10/11) belong to the Boidae family, presenting mostly nematodes, in the dipsadid's samples mainly protozoans were observed and the colubrid's samples were negative. Regarding ectoparasites, 2 species of ticks (Amblyomma dissimile and Ornothodoros turicata) were found in specimens of Boa constrictor, Epicrates maurus and Spilotes pullatus. Conclusions. The identification of parasitic forms in this paper represents a contribution to the knowledge of parasites in snakes ex situ in Colombia. It provides information to develop prophylactic measures against these pathological agents and also allows comparing the data about the parasitic forms found with other researches in the wild and in captivity.

The Harderian gland transcriptomes of Caraiba andreae, Cubophis cantherigerus and Tretanorhinus variabilis, three colubroid snakes from Cuba.

The Harderian gland is a cephalic structure, widely distributed among vertebrates. In snakes, the Harderian gland is anatomically connected to the vomeronasal organ via the nasolacrimal duct, and in some species can be larger than the eyes. The function of the Harderian gland remains elusive, but it has been proposed to play a role in the production of saliva, pheromones, thermoregulatory lipids and growth factors, among others. Here, we have profiled the transcriptomes of the Harderian glands of three non-front-fanged colubroid snakes from Cuba: Caraiba andreae (Cuban Lesser Racer); Cubophis cantherigerus (Cuban Racer); and Tretanorhinus variabilis (Caribbean Water Snake), using Illumina HiSeq2000 100 bp paired-end. In addition to ribosomal and non-characterized proteins, the most abundant transcripts encode putative transport/binding, lipocalin/lipocalin-like, and bactericidal/permeability-increasing-like proteins. Transcripts coding for putative canonical toxins described in venomous snakes were also identified. This transcriptional profile suggests a more complex function than previously recognized for this enigmatic organ.

Systematics of Nothopsini (Serpentes, Dipsadidae), with a new species of Synophis from the Pacific Andean slopes of southwestern Ecuador.

Within Dipsadinae, some recent authors have recognized a tribe Nothopsini containing the genera Diaphorolepis, Emmochliophis, Nothopsis, Synophis, and Xenopholis, on the basis of a number of putative morphological synapomorphies. However, molecular results suggest that Nothopsis, Synophis, and Xenopholis do not form a monophyletic group, while the remaining taxa are unsampled in recent molecular phylogenies. Here, DNA-sequence data for some Diaphorolepis and Synophis species are provided for the first time, as well as additional new sequences for Nothopsis and some Synophis species. Including these and other existing data for nothopsine species, previous studies showing that Nothopsini is not a natural group are corroborated. Nothopsini Cope, 1871 is restricted to Nothopsis. Diaphorolepidini Jenner, 1981 is resurrected and re-delimited to include only Diaphorolepis, Emmochliophis, and Synophis. Finally, Xenopholis remains Dipsadinae incertae sedis. Known material of Diaphorolepidini is reviewed to generate revised and expanded descriptions and diagnoses at the tribe, genus, and species level. Numerous cryptic species are likely present in Synophis bicolor and Synophis lasallei. Finally, a new population from the low-elevation cloud forests of SW Ecuador is reported upon, which is genetically and morphologically distinct from all other species, that is here named Synophis zaheri sp. n.

Description and phylogeny of three new species of Synophis (Colubridae, Dipsadinae) from the tropical Andes in Ecuador and Peru.

The discovery of three new species of Synophis snakes from the eastern slopes of the tropical Andes in Ecuador and Peru is reported. All previous records of Synophis bicolor from eastern Ecuador correspond to Synophis bogerti sp. n., which occurs between 1000-1750 m along a large part of the Amazonian slopes of the Ecuadorian Andes. In contrast, Synophis zamora sp. n. is restricted to southeastern Ecuador, including Cordillera del Cóndor, between 1543-1843 m. Synophis insulomontanus sp. n. is from the eastern slopes of the Andes in central and northern Peru, between 1122-1798 m, and represents the first record of Synophis from this country. All three new species share in common a large lateral spine at the base of the hemipenial body. A molecular phylogenetic tree based on three mitochondrial genes is presented, including samples of Diaphorolepis wagneri. Our tree strongly supports Synophis and Diaphorolepis as sister taxa, as well as monophyly of the three new species described here and Synophis calamitus. Inclusion of Synophis and Diaphorolepis within Dipsadinae as sister to a clade containing Imantodes, Dipsas, Ninia, Hypsiglena and Pseudoleptodeira is also supported.

ResumenSe reporta el descubrimiento de tres especies nuevas de serpientes Synophis de las estribaciones orientales de los Andes tropicales en Ecuador y Perú. Todos los registros previos de Synophis bogerti del oriente ecuatoriano corresponden a Synophis bogertisp. n., la cual ocurre entre 1000­1750 m a lo largo de gran parte de las estribaciones amazónicas de los Andes ecuatorianos. En contraste, Synophis zamorasp. n. se restringe al suroriente de Ecuador, incluyendo la Cordillera del Cóndor, entre 1543­1843 m. Synophis insulomontanussp. n. es de las estribaciones orientales de los Andes del centro y norte del Perú, entre 1122­1798 m, y representa el primer registro de Synophis para este país. Todas las tres especies nuevas comparten en común una espina lateral larga en la base del cuerpo del hemipene. Un árbol molecular filogenético, basado en tres genes mitocondriales es presentado, incluyendo muestras de Diaphorolepis wagneri. Nuestro árbol apoya fuertemente a Synophis y Diaphorolepis como taxa hermanos, así como la monofilia de las tres especies descritas y de Synophis calamitus. La inclusión de Synophis y Diaphorolepis dentro de Dipsadinae, como hermanas a un clado que contiene a Imantodes, Dipsas, Ninia, Hypsiglena y Pseudoleptodeira también es apoyada.

A new species of blunt-headed vine snake (Colubridae, Imantodes) from the Chocó region of Ecuador.

We describe a new species of Imantodes from the Chocó region of northwestern Ecuador. The new species differs most significantly from all other congeners in lacking a loreal scale. We analyze the phylogenetic relationships among species of Imantodes based on two mitochondrial genes, and postulate that the new species and Imantodes lentiferus are sister taxa. A key to the species of Imantodes from Ecuador is presented.

Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with an emphasis on South American Xenodontines: a revised classification and descriptions of new taxa

We present a molecular phylogenetic analysis of caenophidian (advanced) snakes using sequences from two mitochondrial genes (12S and 16S rRNA) and one nuclear (c-mos) gene (1681 total base pairs), and with 131 terminal taxa sampled from throughout all major caenophidian lineages but focussing on Neotropical xenodontines. Direct optimization parsimony analysis resulted in a well-resolved phylogenetic tree, which corroborates some clades identified in previous analyses and suggests new hypotheses for the composition and relationships of others. The major salient points of our analysis are: (1) placement of Acrochordus, Xenodermatids, and Pareatids as successive outgroups to all remaining caenophidians (including viperids, elapids, atractaspidids, and all other "colubrid" groups); (2) within the latter group, viperids and homalopsids are sucessive sister clades to all remaining snakes; (3) the following monophyletic clades within crown group caenophidians: Afro-Asian psammophiids (including Mimophis from Madagascar), Elapidae (including hydrophiines but excluding Homoroselaps), Pseudoxyrhophiinae, Colubrinae, Natricinae, Dipsadinae, and Xenodontinae. Homoroselaps is associated with atractaspidids. Our analysis suggests some taxonomic changes within xenodontines, including new taxonomy for Alsophis elegans, Liophis amarali, and further taxonomic changes within Xenodontini and the West Indian radiation of xenodontines. Based on our molecular analysis, we present a revised classification for caenophidians and provide morphological diagnoses for many of the included clades; we also highlight groups where much more work is needed. We name as new two higher taxonomic clades within Caenophidia, one new subfamily within Dipsadidae, and, within Xenodontinae five new tribes, six new genera and two resurrected genera. We synonymize Xenoxybelis and Pseudablabes with Philodryas; Erythrolamprus with Liophis; and Lystrophis and Waglerophis with Xenodon.

Este trabalho apresenta uma análise filogenética molecular das serpentes avançadas (Caenophidia), realizada com base na análise de seqüências de dois genes mitocondriais (rRNA 12S e 16S) e de um gene nuclear (c-mos; 1681 pares de bases no total) e com 131 táxons terminais, amostrados a partir das principais linhagens de Caenophidia, com ênfase nos xenodontíneos neotropicais. A análise de parcimônia dos dados mediante otimização direta resultou em uma árvore filogenética bem resolvida que, por um lado, corrobora alguns dos clados identificados em análises anteriores e por outro, estabelece novas hipóteses sobre a composição de outros grupos e do relacionamento entre eles. Os principais resultados obtidos salientam: (1) a alocação de Achrochordus, xenodermatídeos e pareatídeos como grupos externos sucessivos de todos os demais cenofídios (incluindo viperídeos, elapídeos, atractaspidídeos e todos os grupos de "colubrídeos"); (2) que, em relação ao último grupo, viperídeos e homalopsídeos podem ser considerados como clados irmãos dos demais; (3) a existência, dentro do grande grupo dos cenofidia, dos seguintes sub-grupos: psamophiídeos afro-asiáticos (incluindo o gênero Mimophis, de Madagascar), Elapidae (incluindo os hidrophiíneos, mas excluindo Homoroselaps, associado aos atractaspidídeos), Pseudoxyrhophiinae, Colubrinae, Natricinae, Dipsadinae e Xenodontinae. A análise sugere algumas alterações de cunho taxonômico dentro dos xenodontíneos, incluindo realocações genéricas para Alsophis elegans, Liophis amarali e modificações substanciais em relação a Xenodontini e à radiação dos xenodontíneos das Antilhas. Também é a aqui apresentada uma revisão da classificação de Caenophidia, baseada inicialmente nas análises moleculares, mas provendo diagnoses morfológicas para muitos dos clados incluídos, realçando os grupos que ainda merecem atenção especial no futuro. São aqui nomeados originalmente dois grandes clados dentro de Caenophidia, uma nova subfamília dentro de Dipsadidae e, dentro de Xenodontinae, cinco novas tribos e seis novos gêneros, sendo ainda dois gêneros revalidados. Os gêneros Xenoxybelis e Pseudablabes são considerados sinônimos de Philodryas; Erythrolamprus, sinônimo de Liophis; Lystrophis e Waglerophis, sinônimos de Xenodon.

Molecular phylogeny of advanced snakes (Serpentes, Caenophidia) with an emphasis on South American Xenodontines: a revised classification and descriptions of new taxa

We present a molecular phylogenetic analysis of caenophidian (advanced) snakes using sequences from two mitochondrial genes (12S and 16S rRNA) and one nuclear (c-mos) gene (1681 total base pairs), and with 131 terminal taxa sampled from throughout all major caenophidian lineages but focussing on Neotropical xenodontines. Direct optimization parsimony analysis resulted in a well-resolved phylogenetic tree, which corroborates some clades identified in previous analyses and suggests new hypotheses for the composition and relationships of others. The major salient points of our analysis are: (1) placement of Acrochordus, Xenodermatids, and Pareatids as successive outgroups to all remaining caenophidians (including viperids, elapids, atractaspidids, and all other "colubrid" groups); (2) within the latter group, viperids and homalopsids are sucessive sister clades to all remaining snakes; (3) the following monophyletic clades within crown group caenophidians: Afro-Asian psammophiids (including Mimophis from Madagascar), Elapidae (including hydrophiines but excluding Homoroselaps), Pseudoxyrhophiinae, Colubrinae, Natricinae, Dipsadinae, and Xenodontinae. Homoroselaps is associated with atractaspidids. Our analysis suggests some taxonomic changes within xenodontines, including new taxonomy for Alsophis elegans, Liophis amarali, and further taxonomic changes within Xenodontini and the West Indian radiation of xenodontines. Based on our molecular analysis, we present a revised classification for caenophidians and provide morphological diagnoses for many of the included clades; we also highlight groups where much more work is needed. We name as new two higher taxonomic clades within Caenophidia, one new subfamily within Dipsadidae, and, within Xenodontinae five new tribes, six new genera and two resurrected genera. We synonymize Xenoxybelis and Pseudablabes with Philodryas; Erythrolamprus with Liophis; and Lystrophis and Waglerophis with Xenodon.

Este trabalho apresenta uma análise filogenética molecular das serpentes avançadas (Caenophidia), realizada com base na análise de seqüências de dois genes mitocondriais (rRNA 12S e 16S) e de um gene nuclear (c-mos; 1681 pares de bases no total) e com 131 táxons terminais, amostrados a partir das principais linhagens de Caenophidia, com ênfase nos xenodontíneos neotropicais. A análise de parcimônia dos dados mediante otimização direta resultou em uma árvore filogenética bem resolvida que, por um lado, corrobora alguns dos clados identificados em análises anteriores e por outro, estabelece novas hipóteses sobre a composição de outros grupos e do relacionamento entre eles. Os principais resultados obtidos salientam: (1) a alocação de Achrochordus, xenodermatídeos e pareatídeos como grupos externos sucessivos de todos os demais cenofídios (incluindo viperídeos, elapídeos, atractaspidídeos e todos os grupos de "colubrídeos"); (2) que, em relação ao último grupo, viperídeos e homalopsídeos podem ser considerados como clados irmãos dos demais; (3) a existência, dentro do grande grupo dos cenofidia, dos seguintes sub-grupos: psamophiídeos afro-asiáticos (incluindo o gênero Mimophis, de Madagascar), Elapidae (incluindo os hidrophiíneos, mas excluindo Homoroselaps, associado aos atractaspidídeos), Pseudoxyrhophiinae, Colubrinae, Natricinae, Dipsadinae e Xenodontinae. A análise sugere algumas alterações de cunho taxonômico dentro dos xenodontíneos, incluindo realocações genéricas para Alsophis elegans, Liophis amarali e modificações substanciais em relação a Xenodontini e à radiação dos xenodontíneos das Antilhas. Também é a aqui apresentada uma revisão da classificação de Caenophidia, baseada inicialmente nas análises moleculares, mas provendo diagnoses morfológicas para muitos dos clados incluídos, realçando os grupos que ainda merecem atenção especial no futuro. São aqui nomeados originalmente dois grandes clados dentro de Caenophidia, uma nova subfamília dentro de Dipsadidae e, dentro de Xenodontinae, cinco novas tribos e seis novos gêneros, sendo ainda dois gêneros revalidados. Os gêneros Xenoxybelis e Pseudablabes são considerados sinônimos de Philodryas; Erythrolamprus, sinônimo de Liophis; Lystrophis e Waglerophis, sinônimos de Xenodon.

Redescription of Atractus albuquerquei (Serpentes: Colubridae: Dipsadinae), with comments on geographical distribution and intraspecific variation

Atractus albuquerquei Cunha and Nascimento, 1983 was previously known from a holotype from eastern Pará, and 15 specimens from Rondônia and Acre, all in Brazil. We report on 23 additional specimens from the Brazilian states of Rondônia, Goiás, Mato Grosso, and Mato Grosso do Sul. These specimens extend the known range of A. albuquerquei substantially, and beyond the southern limits of the Amazon basin. The holotype of A. albuquerquei is redescribed and intraspecific variation in external morphology, hemipenes, and colour is documented. Sexual dimorphism exists in total length, and number of ventral (significantly greater in females) and subcaudal scales (greater in males). There is a significant correlation between number of subcaudal scales and longitude (decreasing from East to West) for both males and females.

Atractus albuquerquei Cunha & Nascimento, 1983 era conhecida apenas do holótipo procedente do leste do estado do Pará e de 15 espécimes dos estados de Rondônia e Acre, no Brasil. Registramos aqui 23 espécimes adicionais provenientes dos estados de Rondônia, Goiás, Mato Grosso e Mato Grosso do Sul. Estes exemplares ampliam a área de distribuição conhecida de A. albuquerquei, para além do limite sul da bacia amazônica. O holótipo de A. albuquerquei é redescrito e a variação intraespecífica da morfologia externa, dos hemipenis e da coloração dos exemplares estudados é analizada. Foi detectado dimorfismo sexual no comprimento total do corpo bem como no número de ventrais (maior nas fêmeas) e de subcaudais (maior nos machos). Foi notada uma correlação significativa entre o número de escamas subcaudais e a longitude (que diminuem de leste para oeste) em ambos os sexos.

Uma nova espécie do gênero Atractus wagler, 1928 (Colubridae: Dipsadinae) do Cerrado do Brasil Central

Atractus edioi sp. n. is described from the region of the Cana Brava hydroelectric power plant, located on the extreme northern state of Goiás, municipality of Minaçu, within the limits of the Cerrado ecosystem of Central Brazil. It can be distinguished from other Atractus by the combination of a temporal formula 1+1, 5 supralabials, supralabials 2-3 bordering the orbit, 6 infralabials, infralabials 1-3 in contact with the anterior genials, 15 dorsal scales rows and a color pattern of dark colored spots on a ground color of the body.

Atractus edioi sp. n. é descrita para a região da usina hidrelétrica Cana Brava, localizada no extremo norte do Estado de Goiás, município de Minaçu, dentro dos limites do ecossistema Cerrado no Brasil Central. Esta espécie se distingue das outras espécies de Atractus pela combinação da fórmula temporal 1+1, 5 supralabiais, supralabiais 2-3 margeando a órbita, 6 infralabiais, infralabiais 1-3 em contato com as gulares anteriores, 15 escamas nas fileiras dorsais e um padrão de coloração dorsal de manchas escuras sobre um fundo marrom-claro.

Uma nova espécie do gênero Atractus wagler, 1928 (Colubridae: Dipsadinae) do Cerrado do Brasil Central

Atractus edioi sp. n. is described from the region of the Cana Brava hydroelectric power plant, located on the extreme northern state of Goiás, municipality of Minaçu, within the limits of the Cerrado ecosystem of Central Brazil. It can be distinguished from other Atractus by the combination of a temporal formula 1+1, 5 supralabials, supralabials 2-3 bordering the orbit, 6 infralabials, infralabials 1-3 in contact with the anterior genials, 15 dorsal scales rows and a color pattern of dark colored spots on a ground color of the body.

Atractus edioi sp. n. é descrita para a região da usina hidrelétrica Cana Brava, localizada no extremo norte do Estado de Goiás, município de Minaçu, dentro dos limites do ecossistema Cerrado no Brasil Central. Esta espécie se distingue das outras espécies de Atractus pela combinação da fórmula temporal 1+1, 5 supralabiais, supralabiais 2-3 margeando a órbita, 6 infralabiais, infralabiais 1-3 em contato com as gulares anteriores, 15 escamas nas fileiras dorsais e um padrão de coloração dorsal de manchas escuras sobre um fundo marrom-claro.

Redescription of Atractus albuquerquei (Serpentes: Colubridae: Dipsadinae), with comments on geographical distribution and intraspecific variation

Atractus albuquerquei Cunha and Nascimento, 1983 was previously known from a holotype from eastern Pará, and 15 specimens from Rondônia and Acre, all in Brazil. We report on 23 additional specimens from the Brazilian states of Rondônia, Goiás, Mato Grosso, and Mato Grosso do Sul. These specimens extend the known range of A. albuquerquei substantially, and beyond the southern limits of the Amazon basin. The holotype of A. albuquerquei is redescribed and intraspecific variation in external morphology, hemipenes, and colour is documented. Sexual dimorphism exists in total length, and number of ventral (significantly greater in females) and subcaudal scales (greater in males). There is a significant correlation between number of subcaudal scales and longitude (decreasing from East to West) for both males and females.

Atractus albuquerquei Cunha & Nascimento, 1983 era conhecida apenas do holótipo procedente do leste do estado do Pará e de 15 espécimes dos estados de Rondônia e Acre, no Brasil. Registramos aqui 23 espécimes adicionais provenientes dos estados de Rondônia, Goiás, Mato Grosso e Mato Grosso do Sul. Estes exemplares ampliam a área de distribuição conhecida de A. albuquerquei, para além do limite sul da bacia amazônica. O holótipo de A. albuquerquei é redescrito e a variação intraespecífica da morfologia externa, dos hemipenis e da coloração dos exemplares estudados é analizada. Foi detectado dimorfismo sexual no comprimento total do corpo bem como no número de ventrais (maior nas fêmeas) e de subcaudais (maior nos machos). Foi notada uma correlação significativa entre o número de escamas subcaudais e a longitude (que diminuem de leste para oeste) em ambos os sexos.