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Featured researches published by Robson W. Ávila.


Comparative Parasitology | 2010

Helminths from Seven Species of Lizards (Reptilia: Squamata) at the Cerrado of Mato Grosso do Sul State, Brazil

Robson W. Ávila; Franco L. Souza; Reinaldo José da Silva

Abstract Sixteen specimens representing 7 species of lizards (Hoplocercus spinosus, Ophiodes striatus, Polychrus acutirostris, Stenocercus caducus, Tropidurus guarani, Tropidurus itambere, and Tupinambis merianae) collected in the Cerrado biome at the Brazilian state Mato Grosso do Sul were examined for helminths. Nine species of nematodes were recovered from lizard hosts (Cruzia travassosi, Cyrtosomum sp., Diaphanocephalus galeatus, Gynaecometra bahiensis, Pharyngodon cesarpintoi, Physaloptera sp., Skrjabinellazia intermedia, Strongyluris oscari, and an unidentified species of nematode). Five new host records and 3 new locality records were reported.


Journal of Helminthology | 2009

Helminths of the teiid lizard Kentropyx calcarata (Squamata) from an Amazonian site in western Brazil

Robson W. Ávila; R.J. da Silva

Despite being conspicuous members of neotropical lizard communities, aspects of the life history of many teiid lizard species are poorly known, especially endoparasites infecting the genus Kentropyx. We studied seven specimens of K. calcarata collected at an Amazonian site in Mato Grosso state, Central Brazil in 2007. Four species of helminth were recovered: Oswaldocruzia sp., Piratuba digiticauda, Physaloptera retusa and Physalopteroides venancioi. Piratuba digiticauda, a body-cavity, parasite had the highest prevalence (42.9%), whereas the stomach parasites P. venancioi and P. retusa presented the highest intensity of infection and abundance, respectively. Moreover, this is the first report of Oswaldocruzia sp., P. digiticauda and P. venancioi in K. calcarata and new locality records for all nematodes were assigned.


Check List | 2009

Amphibia, Anura, Centrolenidae, Cochranella adenocheira : distribution and range extension, Brazil

Luís Felipe Toledo; Olívia G. S. Araújo; Robson W. Ávila; Ricardo A. Kawashita-Ribeiro; Drausio Honorio Morais; Diego F. Cisneros-Heredia

Cochranella adenocheira Harvey and Nooan 2005 was described based on two specimens collected in the Amazon region of Bolivia, in the Serranía de Huanchaca, Departamento de Santa Cruz (Harvey and Nooan 2005). It is included in the Family Centrolenidae, but as Incertae sedis in regard to its genera (see Guayasmin et al. 2009). Caldwell (2009) reported the second known locality of this species and the first for Brazil, from the state of Mato Grosso (Figure 1). However, Cochranella adenocheira is not included in the Brazilian official list of species (SBH 2009; see also Frost 2009). During recent field expeditions, we collected centrolenid specimens in the southern Brazilian Amazon basin that we identified as Cochranella adenocheira (Figure 2).


Journal of Helminthology | 2010

Nematode infection in the lizard Bogertia lutzae (Loveridge, 1941) from the Atlantic forest in north-eastern Brazil

Robson W. Ávila; L.A. Anjos; U. Gonçalves; E.M.X. Freire; Waltécio de Oliveira Almeida; R.J. da Silva

Endoparasites associated with the small bromelicolous lizard Bogertia lutzae, a poorly studied phyllodactylid inhabitant of north-eastern Brazil, were studied. Fifty-seven specimens collected from the Atlantic Forest of Alagoas state were dissected. Only one species of parasite, the nematode Spauligodon oxkutzcabiensis, was found, with a prevalence of 22.8%. The intensity of infection was 2.62 +/- 1.19, and neither the prevalence nor mean intensity differed between the sexes. There was no correlation between lizard body size and intensity of infection. An aggregated pattern of distribution (D = 0.813) of S. oxkutzcabiensis was found in this lizard host population. Bogertia lutzae represents a new host recorded for S. oxkutzcabiensis, a parasite reported for the first time for Brazil.


Zootaxa | 2015

Two new species of Amazophrynella (Amphibia: Anura: Bufonidae) from Loreto, Peru

Rommel R. Rojas; Vinícius Tadeu De Carvalho; Robson W. Ávila; Izeni P. Farias; Marcelo Gordo; Tomas Hrbek

Amazophrynella is a taxonomically poorly known bufonid genus with a pan-Amazonian distribution. A large part of this ambiguity comes from taxonomic uncertainties regarding the type species A. minuta. In this study we compare morphological and molecular data of topotypic specimens of A. minuta with all other nomical congeneric species. Based on these comparisons, we describe two new species. The first species, A. amazonicola sp. nov., differs from other recognized congeners by having a tip of snout with a small triangular protrusion (in dorsal and lateral view), spiculated body and basal webbing on fingers I and II. The second species, A. matses sp. nov., differs from congeners by the smallest snout to vent length of the genus, edges of nasal protrusion dilated and elliptical shape palmar tubercles. The two species are allopatric, where the first species is known to be associated with white sand forests (=campinaranas), while the second inhabits upland (=terra firme) forests. Both species are diagnosable by a series of substitutions in the 16S rDNA, and both species are highly divergent from their sister taxa (p-distances range from 7-14%).


Zootaxa | 2013

A new species of Amazophrynella (Anura:Bufonidae) from the southwestern part of the Brazilian Guiana Shield

Rommel R. Rojas; Vinícius Tadeu De Carvalho; Marcelo Gordo; Robson W. Ávila; Izeni P. Farias; Tomas Hrbek

Amazophrynella is a genus of the family Bufonidae, currently represented by three species. The type species of the genus, Amazophrynella minuta, however, is a complex of species occurring throughout the Amazonian biome. This group remains problematic taxonomically; the difficulty lays principally in the lack of diagnostic characters in the original description of A. minuta, the lack of molecular data and refined taxonomic comparison of individuals through its wide distribution. We describe a new species of the genus Amazophrynella, distributed in the southwestern part of the Guiana Shield of Brazil based on a series of morphological and molecular characters. The new species differs from others of the genus by presenting a slightly truncated triangular snout, ventral texture covered by many fine granules, white belly covered with black spots and by fifteen molecular autapomorphies in the 16S rDNA fragment. Uncorrected p-distances of a fragment of the 16S mitochondrial rDNA gene revealed high divergence among other Amazophrynella species (9%-14%). Additionally we provide a new diagnosis of topotypic material of Amazophrynella minuta including molecular data. Our results show the existence of a subestimated diversity in the genus Amazophrynella.xa0


ZooKeys | 2016

Uncovering the diversity in the Amazophrynella minuta complex: integrative taxonomy reveals a new species of Amazophrynella (Anura, Bufonidae) from southern Peru.

Rommel R. Rojas; Juan C. Chaparro; Vinícius Tadeu De Carvalho; Robson W. Ávila; Izeni P. Farias; Tomas Hrbek; Marcelo Gordo

Abstract A new species of the genus Amazophrynella (Anura, Bufonidae) is described from the departments of Madre de Dios, Cusco and Junin in Peru. An integrative taxonomy approach is used. A morphological diagnosis, morphometrics comparisons, description of the advertisement call, and the phylogenetic relationships of the new species are provided. Amazophrynella javierbustamantei sp. n. differs from other species of Amazophrynella by: intermediate body-size (snout-vent length 14.9 mm in males, n = 26 and 19.6 mm in females, n = 20), tuberculate skin texture of body, greatest hand length of the Amazophrynella spp. (3.6 mm in males, n = 26 and 4.6 mm in females, n = 20), venter coloration yellowish, tiny rounded black points covering the venter, and thirteen molecular autapomorphies in the 16S RNA gene. Its distribution varies from 215 to 708 m a.s.l. This discovery highlights the importance of the remnant forest in preserving the biodiversity in Peru, and increase in seven the species formally described in the genus Amazophrynella.


Zootaxa | 2018

Description of the advertisement calls of four species of Amazophrynella (Anura:Bufonidae)

Rommel R. Rojas; Vinícius Tadeu De Carvalho; Robson W. Ávila; Ricardo A. Kawashita-Ribeiro; Tomas Hrbek; Marcelo Gordo

Amazophrynella comprises 11 small bufonid species with a pan-Amazonian distribution (Fouquet et al. 2012a, b; Rojas et al. 2016, Rojas et al. 2018). All species inhabit the forest leaf litter, breed in seasonal puddles and are diurnally and nocturnally active (Fouquet et al. 2012b; Rojas et al. 2014; 2015; 2016). Until now only one nominal species, A. javierbustamantei, and two putative lineages-A. moisesii (Rio Yuyapichis, Peru) and A. siona (Santa Cecilia, Ecuador)-had their advertisement calls formally described (Duellman 1978; Schlüter 1981; Rojas et al. 2016). Herein, we described for the first time the advertisement calls from additional four species of Amazophrynella.


PeerJ | 2018

A Pan-Amazonian species delimitation: high species diversity within the genus Amazophrynella (Anura: Bufonidae)

Rommel R. Rojas; Antoine Fouquet; Santiago R. Ron; Emil José Hernández-Ruz; Paulo R. Melo-Sampaio; Juan C. Chaparro; Richard C. Vogt; Vinícius Tadeu De Carvalho; Leandra Cardoso Pinheiro; Robson W. Ávila; Izeni P. Farias; Marcelo Gordo; Tomas Hrbek

Amphibians are probably the most vulnerable group to climate change and climate-change associate diseases. This ongoing biodiversity crisis makes it thus imperative to improve the taxonomy of anurans in biodiverse but understudied areas such as Amazonia. In this study, we applied robust integrative taxonomic methods combining genetic (mitochondrial 16S, 12S and COI genes), morphological and environmental data to delimit species of the genus Amazophrynella (Anura: Bufonidae) sampled from throughout their pan-Amazonian distribution. Our study confirms the hypothesis that the species diversity of the genus is grossly underestimated. Our analyses suggest the existence of eighteen linages of which seven are nominal species, three Deep Conspecific Lineages, one Unconfirmed Candidate Species, three Uncategorized Lineages, and four Confirmed Candidate Species and described herein. We also propose a phylogenetic hypothesis for the genus and discuss its implications for historical biogeography of this Amazonian group.


Zootaxa | 2010

A new species of the Rhinella margaritifera group (Anura: Bufonidae) from Brazilian Pantanal

Robson W. Ávila; André Pansonato; Christine Strüssmann

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Marcelo Gordo

Federal University of Amazonas

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Rommel R. Rojas

Federal University of Amazonas

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Tomas Hrbek

Federal University of Amazonas

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Izeni P. Farias

Federal University of Amazonas

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Christine Strüssmann

Universidade Federal de Mato Grosso

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Franco L. Souza

Federal University of Mato Grosso do Sul

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Ricardo A. Kawashita-Ribeiro

Universidade Federal de Mato Grosso

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Ana Luiza C. Campos

Federal University of Mato Grosso do Sul

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André Pansonato

Universidade Federal de Mato Grosso

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