36 research outputs found
A New Two-Pored Amphisbaena Linnaeus, 1758, \ud from Western Amazonia, Brazil \ud (Amphisbaenia: Reptilia)
Recent efforts to improve sampling of Brazilian biodiversity have yielded a number of undescribed species of amphisbaenids. Herein, we describe a new species of small, two-pored Amphisbaena from western Brazilian Amazonia. The new species can be distinguished from all congeners by the combination of the following characters: two precloacal pores arranged in a continuous series; snout rounded in lateral and dorsal views; tip of tail rounded; 233–250 body annuli; 20–24 caudal annuli; autotomy sites on caudal annuli 6–9; 10 dorsal and 12–14 ventral segments per annulus at midbody; absence of postmalars; suture between frontals slightly smaller than parietal and nasal sutures; and tail short relative to body length (tail length/body length = 0.10). The new species inhabits the rain forest and small patches of savanna vegetation within the Amazon Forest. A Bayesian analysis based on two mitochondrial (16S and ND2) and three nuclear (cmos, BNDF and RAG1) markers recovered the new species as sister to a clade formed by A. hastata + A. cuiabana; however, support for this relationship is low. Genetic divergence between populations from both sides of the middle Madeira River is low.IBAMA (permit CGFAP 260/2010
A new species of Atractus (Serpentes: Dipsadidae) from Serra do Cipó, Espinhaço Range, Southeastern Brazil, with proposition of a new species group to the genus
We describe a new species of Atractus from Serra do Cipó, at the southeastern versant of Serra do Espinhaço, an inland mountain range nearly parallel to the Brazilian Atlantic coast. The new species is morphologically similar to A. paraguayensis and A. potschi with which it shares: 15 dorsal scale rows; white occipital region in juvenile specimens; dorsal ground color reddish pink to red (in life) with alternate black transversal spots, blotches or transversal bands; seven upper and lower labial scales; ventrals and subcaudals creamish white; hemipenis slightly bilobed, semicapitate and semicalyculate. The new species differs from both taxa mainly on the basis of exclusive coloration characters (number and shape of transversal bands) and hemipenial morphology (median face of the lobes without ornamentation), besides punctual meristic (number of ventral scales and maxillary teeth) and morphometric (adult snout-vent length) differences. Finally, we provide a discussion regarding the potential affinities of the new species and we redefine some Atractus species groups in order to better accommodate species sharing unique combinations of morphological characters.Descrevemos uma nova espécie de Atractus da Serra do Cipó, na vertente sudeste da Serra do Espinhaço, uma cadeia montanhosa continental aproximadamente paralela à costa Atlântica brasileira. A nova espécie é morfologicamente similar a A. paraguayensis e A. potschi com as quais compartilha: 15 séries de escamas dorsais; região occipital branca em espécimes jovens; coloração dorsal de fundo variando de rosa avermelhado a vermelho (em vida) com pontuações, manchas e/ou bandas transversais pretas; sete supralabiais e infralabiais; ventrais e subcaudais creme esbranquiçado; hemipênis levemente bilobado, semicapitulado e semicaliculado. A nova espécie difere de ambos os táxons principalmente a partir de caracteres exclusivos de coloração (número e forma das bandas transversais), da morfologia hemipeniana (face mediana dos lobos sem ornamentação) além de diferenças merísticas (número de escamas ventrais e dentes maxilares) e morfométricas (comprimento rostro-cloacal dos adultos). Apresenta-se uma discussão sobre as possíveis afinidades da nova espécie e redefinem-se alguns grupos de espécies de Atractus no sentido de acomodar melhor as espécies que compartilham combinações únicas de caracteres morfológicos
Phylogeny and systematics of jararacussu species group of Bothrops (Serpentes, Crotalinae), with test of biogeographic hypothesis to the past connection Amazonia-Atlantic Forest
O contato pretérito Amazônia-Mata Atlântica vem sendo recorrentemente citado na literatura para diversos grupos da fauna Neotropical e teria ocorrido por diferentes rotas geográficas e períodos temporais. Segundo esta hipótese, em períodos quentes e úmidos as florestas se expandiram provocando retração/fragmentação das áreas abertas, ao passo que em períodos frios e secos, o inverso ocorreria. Assim, utilizando-se de crotalíneos como modelo, esta tese pretende: (1) testar o pretérito contato Amazônia-Mata Atlântica, assim como o tempo de separação entre as linhagens relictuais nesses ambientes florestados, elucidando a história demográfica das espécies de Bothrops do grupo jararacuçu, do grupo atrox e de B. bilineatus; (2) paralelamente Crotalus durissus, espécie associada à diagonal de áreas abertas da América do Sul (Caatinga, Cerrado e Chaco), foi utilizada para testar a ocorrência de expansão desses ambientes, o que levaria a quebra da hipotetizada ponte florestada Amazônia-Mata Atlântica. Através de dataset multi-locus sob Inferência Bayesiana (quatro genes mitocondriais e cinco nucleares) foram testadas as relações filogenéticas e filogeográficas entre as amostras em Bothrops e Crotalus. Cenários históricos alternativos foram testados com base em simulações coalescentes e ABC (approximate Bayesian computation). Adicionalmente, foi empregado teste de delimitação de linhagens evolutivas para o reconhecimento da diversidade, a nível de espécie, em cada grupo estudado, usando a implementação Bayesiana do algoritimo Generalized Mixed Yule-Coalescent. Os resultados filogenéticos e análises de delimitação de espécies indicam diversidade críptica para os grupos jararacussu, atrox e taeniatus. Os testes de cenários históricos sugerem (1) múltiplas conexões florestais Amazônia-Mata Atlântica nos últimos 2.5 milhões de anos, com intercâmbio faunístico em ambas as direções e (2) expansão das áreas abertas do Cerrado e Caatinga em sincronia temporal com perda de conectividade florestal Amazônia-Mata Atlântica durante o Pleistoceno tardio (3) que a formação e estabilização do Rio Amazonas teve influência na diversificação do grupo jararacuçu, gerando diversidade. Os resultados trazem informações sobre o dinamismo histórico das paisagens florestadas e abertas no Neotrópico ao longo do tempo, assim como o papel dos rios amazônicos na diversificação da fauna. Adicionalmente, os resultados apontam para instabilidade taxonômica e diversidade críptica em diversos grupos em Bothrops e em Crotalus durissus, revelando a necessidade do aprofundamento sistemático para essas serpentes venenosas de importância médicaThe hypotetized historical contact Amazon-Atlantic Forest has been recurrently cited in the literature for several groups of Neotropical fauna and would have occurred by different geographic routes and time periods. According to this hypothesis, in hot and humid periods the forests expanded causing retraction / fragmentation of the open areas, while in cold and dry periods, the reverse would occur. Thus, by using Neotropical pit vipers as a model, this thesis aims to: (1) test the historical forest contact Amazon-Atlantic Forest, as well as the time of separation between relict lineages in these forested environments, elucidating the demographic history of Bothrops species from jararacussu group, atrox group and B. bilineatus; (2) Crotalus durissus, a species associated with the diagonal of open areas of South America (Caatinga, Cerrado and Chaco), was used in parallel to test the occurrence of expansion of these environments, which would lead to the breakage of the hypothetical Amazon-Atlantic Forest forested bridge. Phylogenetic and phylogeographic relationships between samples of Bothrops and Crotalus were tested through a multi-locus dataset (four mitochondrial genes and five nuclear) under Bayesian Inference. Alternative historical scenarios were tested based on coalescent simulations and ABC (approximate Bayesian computation). In addition, was inferred independently evolving lineages to recognized species diversity in each group studied, using Bayesian implementation of the molecular species delimitation algorithm Generalized Mixed Yule-Coalescent. Phylogenetic results and analyzes of species delimitation indicate cryptic diversity for the groups jararacussu, atrox and taeniatus. The tests of historical scenarios suggest (1) multiple Amazon-Atlantic Forest forest connections in the last 2.5 million years, with faunal exchange in both directions and (2) expansion of the open areas of the Cerrado and Caatinga in temporal synchrony with loss of forest bridge Amazon-Atlantic Forest during late Pleistocene (3) that the formation and stabilization of the Amazon River influenced the diversification of the jararacussu group, generating diversity. The results provide information on the historical dynamism of forested and open landscapes in the Neotropics over time, as well as the role of Amazonian rivers in the diversification of fauna. Moreover, the results point to taxonomic instability and cryptic diversity in several groups within Brothrops and Crotalus durissus, revealing the need for systematic deepening for these medically important venemous snake
Review of Bothrops bilineatus (Serpentes, Viperidae) based on morphological and molecular data
Bothrops bilineatus é uma das seis espécies presentes no grupo taeniatus, é reconhecida atualmente por duas sub-espécies: B. b. smaragdinus que se distribui pelo oeste Amazônico e B. b. bilineatus com distribuição disjunta pela Amazônia e Mata Atlântica. Este trabalho tem como objetivo testar a validade das duas sub-espécies com base em ferramentas moleculares, morfométricas, merísticas, hemipenianas e osteológicas, reconhecendo e delimitando as linhagens encontradas. Pretende-se ainda investigar as relações filogeográficas entre as populações ao longo da sua distribuição, analisando o tempo de divergência e os possíveis eventos associados a sua diversificação. Além disso, pretende-se comparar a variação molecular e hemipeniana de B. bilineatus com B. taeniatus (espécie filogeneticamente próxima) e as existentes nos outros grupos de espécies do gênero. Os resultados mostram que a variação genética e hemipeniana encontram se em diferentes níveis ao longo dos grupos de espécies em Bothrops, fornecendo informação relevante a nível intra e inter-específico. Foram recuperados seis clados estruturados para Bothrops bilineatus, representando quatro linhagens independentes e diagnosticáveis com base conjunta nos caracteres morfológicos, hemipenianos, osteológicos e moleculares: linhagem 1 - Amazônia central, basal as outras, linhagem 2 - Mata Atlântica+Escudo das Guianas externa às linhagens 3 e 4 Amazônia oeste parte sul e norte, respectivamente. Já para B. taeniatus quatro clados representando três linhagens foram recuperadas com bases nos caracteres moleculares e hemipenianos, porém se faz necessário buscar por mais caracteres morfológicos e osteológicos para melhor delimitar e diagnosticar as linhagens. As mudanças paleoclimáticas e geomorfológicas ocorridas na transição Terciário/Quaternário parecem ser os principais eventos a influenciar na diversificação das linhagens encontradas em Bothrops bilineatus e B. taeniatusBothrops bilineatus is one of six species in the taeniatus group, is now recognized by two subspecies: B. b. smaragdinus that distributes through western Amazon and B. b. bilineatus with disjunct distribution through Amazon and Atlantic Forest. This work aims to test the validity of these two sub-species, based on molecular, morphometric tools, meristic, osteological and hemipenial data, recognizing and delimiting lineages found. We also intend to investigate the phylogeographic relationships among populations throughout its distribution, analyzing the divergence time and possible events associated with it diversification. In addition, we intend to compare the molecular and hemipenial variation presented in B. bilineatus with B. taeniatus (phylogenetically close species) and those in the other groups of the genus. The genetic and hemipenial results show different levels of variation along the groups of Bothrops species, providing significant intra-and inter-specific information. Six clades structured to Bothrops bilineatus were recovered, representing four independent lineages diagnosable with joint based on morphology, hemipenial, osteological and molecular characters: lineage 1 - central Amazon, basal the others, lineage 2 - Atlantic Forest + Guayana Shield region recovered outside the sisters lineages 3 and 4 - western Amazon, southern part and western Amazon, northern part, respectively. As for B. taeniatus four clades representing three lineages were recovered with bases in molecular and hemipenial characters, however it is necessary to search for more morphological and osteological characters to better delimit and diagnose the lineages. Paleoclimatic and geomorphic changes in the transition Tertiary/Quaternary, probably are the major events influencing the diversification of lineages found in Bothrops bilineatus and B. taeniatu
The herpetofauna of the Estação Ecológica de Uruçuí-Una, state of Piauí, Brazil
This work was carried out with the main objective of sampling the herpetofauna of a Cerrado site in the state of Piauí, Brazil, that is influenced by neighboring biomes and one of the least known regions of the domain. The herpetofauna of the different habitats present at Estação Ecológica de Uruçuí-Una (EEUU) was sampled intensively during three campaigns (two during the wet season and one during the dry season). We recorded 90 species, 64 reptiles and 26 anurans, a high local richness when compared to other well-sampled localities of the Cerrado. The rarefaction curve for both anurans and lizards shows that the observed richness is close to real and the richness estimators indicate that undetected species should be added with higher sampling effort. Analysis of co-occurrence shows that the species are not randomly distributed in the landscape, indicating that they use preferentially particular types of habitat. Despite being located in a transitional area and influenced by neighboring biomes, the cluster analysis of similarity suggests that the herpetofauna of the EEUU is typical of the Cerrado. Thereby, the results of this study indicate that the EEUU presents a rich herpetofauna that plays an important role in the conservation of a regional faunistic pool
On the snake Siphlophis worontzowi (Prado, 1940): notes on its distribution, diet and morphological data
We provide geographic data for the poorly known dipsadid Siphlophis worontzowi including the first records to the Tocantins state and on the left bank of Madeira River at Rondônia State. Our data also extend its distribution on Mato Grosso State. We also provide new morphometric, meristic and ecological data to the knowledge of this species
Natural history of Micrablepharus maximiliani (Squamata: Gymnophthalmidae) in a Cerrado region of northeastern Brazil
Micrablepharus maximiliani (Reinhardt & Luetken, 1861) is a microteiid lizard widely distributed in the open areas of South America. Little is known about its ecology and reproductive biology. Here, we analyzed aspects of the natural history of a population of M. maximiliani from a Cerrado area in the state of Piauí, northeastern Brazil. Our results suggest that the reproductive activity of M. maximiliani might be seasonal in the Cerrado, since reproductive females were observed only in the dry season, whereas reproductive males were present in both seasons. Vitellogenic follicles and oviductal eggs were found simultaneously in one female, suggesting that females may produce more than one clutch per season. Sexual dimorphism was observed in body shape, and individuals were mainly restricted to a typical savanna physiognomy. The diet consisted of small arthropods, including spiders, crickets and cockroaches as the most important items.This research was supported by grants from the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ), and Fundação Boticário para a Conservação da Natureza
On the snake Siphlophis worontzowi (Prado, 1940): notes on its distribution, diet and morphological data
We provide geographic data for the poorly known dipsadid Siphlophis worontzowi including the first records to the Tocantins state and on the left bank of Madeira River at Rondônia State. Our data also extend its distribution on Mato Grosso State. We also provide new morphometric, meristic and ecological data to the knowledge of this species