Pablo J. Venegas
Pontificia Universidad Católica del Ecuador
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Publication
Featured researches published by Pablo J. Venegas.
ZooKeys | 2013
César Aguilar; Perry L. Wood; Juan Carlos Cusi; Alfredo Guzmán; Frank Huari; Mikael Lundberg; Emma Mortensen; César Ramírez; Daniel Robles; Juana Suárez; Andres Ticona; Víctor J. Vargas; Pablo J. Venegas; Jack W. Sites
Abstract Species delimitation studies based on integrative taxonomic approaches have received considerable attention in the last few years, and have provided the strongest hypotheses of species boundaries. We used three lines of evidence (molecular, morphological, and niche envelopes) to test for species boundaries in Peruvian populations of the Liolaemus walkeri complex. Our results show that different lines of evidence and analyses are congruent in different combinations, for unambiguous delimitation of three lineages that were “hidden” within known species, and now deserve species status. Our phylogenetic analysis shows that L. walkeri, L. tacnae and the three new species are strongly separated from other species assigned to the alticolor-bibronii group. Few conventional morphological characters distinguish the new species from closely related taxa and this highlights the need to integrate other sources of data to erect strong hypothesis of species limits. A taxonomic key for known Peruvian species of the subgenus Lioalemus is provided.
ZooKeys | 2012
Santiago R. Ron; Pablo J. Venegas; Eduardo Toral; Morley Read; Diego Ortiz; Andrea L. Manzano
Abstract We present a new phylogeny, based on DNA sequences of mitochondrial and nuclear genes, for frogs of the genus Osteocephalus with emphasis in the Osteocephalus buckleyi species complex. Genetic, morphologic, and advertisement call data are combined to define species boundaries and describe new species. The phylogeny shows strong support for: (1) a basal position of Osteocephalus taurinus + Osteocephalus oophagus, (2) a clade containing phytotelmata breeding species, and (3) a clade that corresponds to the Osteocephalus buckleyi species complex. Our results document a large proportion of hidden diversity within a set of populations that were previously treated as a single, widely distributed species, Osteocephalus buckleyi. Individuals assignable to Osteocephalus buckleyi formed a paraphyletic group relative to Osteocephalus verruciger and Osteocephalus cabrerai and contained four species, one of which is Osteocephalus buckleyi sensu stricto and three are new. Two of the new species are shared between Ecuador and Peru (Osteocephalus vilmae sp. n. and Osteocephalus cannatellai sp. n.) and one is distributed in the Amazon region of southern Peru (Osteocephalus germani sp. n.) We discuss the difficulties of using morphological characters to define species boundaries and propose a hypothesis to explain them.
Journal of Herpetology | 2008
Pablo J. Venegas; Josiah H. Townsend; Claudia Koch; Wolfgang Böhme
Abstract Two new species of the genus Phyllodactylus are described based on material collected in the southern portion of Departamento de Amazonas, Peru. Both species are well differentiated from all other South American Phyllodactylus based on characteristics of their morphology. In the case of one species, its large adult size and lack of well-defined rows of strongly keeled scales differentiate it from other Phyllodactylus, whereas in the second species, the presence of an enlarged postanal scale is diagnostic. Both species were collected in the xeric Balsas region of the upper Marañon Valley, and exhibit some similarities to other assemblages of sympatric Phyllodactylus in South America. The Balsas region is an area of endemism that warrants further attention from systematists and conservation biologists.
Molecular Phylogenetics and Evolution | 2015
Omar Torres-Carvajal; Simón E. Lobos; Pablo J. Venegas
Among Neotropical lizards, the geographically widespread gymnophthalmid Cercosaura as currently defined includes lowland and highland taxa from Panama to Argentina, with some species occurring in the northern Andes. In this study we analyze three mitochondrial (12S, 16S, ND4) and one nuclear (c-mos) gene using Bayesian methods to clarify the phylogenetic relationships among most species of Cercosaura based on a well-supported phylogenetic hypothesis that also includes a large sample of other taxa within Cercosaurini. The phylogenetic tree obtained in this paper shows that Cercosaura as currently defined is not monophyletic. Two species from the northern Andes (C. dicra and C. vertebralis) are nested within Pholidobolus, which has been formerly recognized as a major radiation along the Andes of Ecuador and Colombia. Therefore, Cercosaura has probably not diversified in the northern Andes, although the phylogenetic position of C. hypnoides from the Andes of Colombia remains unknown. Tree topology and genetic distances support both recognition of C. ocellata bassleri as a distinct species, C. bassleri, and recognition of C. argula and C. oshaughnessyi as two different species. In the interest of promoting clarity and precision regarding the names of clades of gymnophthalmid lizards, we propose a phylogenetic definition of Cercosaura.
ZooKeys | 2016
María J. Navarrete; Pablo J. Venegas; Santiago R. Ron
Abstract We describe two new species of frogs of the genus Pristimantis from the eastern slopes of the Ecuadorian Andes, at Parque Nacional Llanganates. The new species are characterized by the spiny appearance typical of several species inhabiting montane forests. Pristimantis yanezi sp. n. is most similar to Pristimantis colonensis and Pristimantis incanus but differs from both in groin coloration and by having smaller tubercles on the upper eyelids, heels, and tarsus. Pristimantis llanganati sp. n. is most similar to Pristimantis eriphus and Pristimantis chloronotus. It can be distinguished from Pristimantis eriphus by the color pattern on the scapular region and by having smaller conical tubercles on the dorsum. Pristimantis chloronotus differs from Pristimantis llanganati sp. n. in having a pair of sinuous paravertebral folds. Both new species occur in a region with few amphibian collections and nothing is known about their abundance and ecology. Therefore, it is recommended to assign them to the Data Deficient Red List category. Updated figures of species richness of Pristimantis among biogeographic regions in Ecuador are also presented. Pristimantis reach their highest diversity in Montane Forests of the eastern versant of the Andes. Its species richness across regions cannot be explained by regional area, elevation, temperature, or precipitation. Political endemism in Pristimantis is higher than that of other terrestrial vertebrates.
ZooKeys | 2011
Claudia Koch; Pablo J. Venegas; Antonio García Bravo; Wolfgang Boehme
Abstract We herein describe a new colorful species of Polychrus with a conspicuous sexual dimorphism from the dry forest of the northern portion of Región de La Libertad, Peru. The new species differs from all other Polychrus species, in that this species has very small dorsal scales and thus a higher number of scales around midbody and in the middorsal line from behind the occipital scales to the level of the posterior edge of the thigh. Furthermore, we redescribe Polychrus peruvianus whose original description is short and lacks information on intraspecific variation and sexual dimorphism. Also, we add some information on intraspecific variation and ecology of Polychrus gutturosus. Finally, we synonymize Polychrus spurrelli Boulenger with Polychrus gutturosus.
PLOS ONE | 2017
Marcel A. Caminer; Borja Milá; Martin Jansen; Antoine Fouquet; Pablo J. Venegas; Germán Chávez; Stephen C. Lougheed; Santiago R. Ron
Genetic data in studies of systematics of Amazonian amphibians frequently reveal that purportedly widespread single species in reality comprise species complexes. This means that real species richness may be significantly higher than current estimates. Here we combine genetic, morphological, and bioacoustic data to assess the phylogenetic relationships and species boundaries of two Amazonian species of the Dendropsophus leucophyllatus species group: D. leucophyllatus and D. triangulum. Our results uncovered the existence of five confirmed and four unconfirmed candidate species. Among the confirmed candidate species, three have available names: Dendropsophus leucophyllatus, Dendropsophus triangulum, and Dendropsophus reticulatus, this last being removed from the synonymy of D. triangulum. A neotype of D. leucophyllatus is designated. We describe the remaining two confirmed candidate species, one from Bolivia and another from Peru. All confirmed candidate species are morphologically distinct and have much smaller geographic ranges than those previously reported for D. leucophyllatus and D. triangulum sensu lato. Dendropsophus leucophyllatus sensu stricto occurs in the Guianan region. Dendropsophus reticulatus comb. nov. corresponds to populations in the Amazon basin of Brazil, Ecuador, and Peru previously referred to as D. triangulum. Dendropsophus triangulum sensu stricto is the most widely distributed species; it occurs in Amazonian Ecuador, Peru and Brazil, reaching the state of Pará. We provide accounts for all described species including an assessment of their conservation status.
Zootaxa | 2013
Pablo J. Venegas; Vilma Duran; Karla García-Burneo
We describe a new species of Stenocercus from an interandean valley of the upper Río Huallaga on the Amazonian slope of central Peru (Región Huánuco), at an elevation of 1700-1900 m. The new species differs from other Stenocercus, except S. boettgeri, S. haenschi, S. humeralis, and S. varius, by the combination of the following characters: presence of granular scales on the posterior surface of the thighs, enlarged vertebrals, three caudal whorls per autotomic segment, a medially complete antegular fold, non-spinose caudals, and by males lacking a black transverse band on the ventral surface of the neck. However, the new Stenocercus differs from these, with the exception of S. humeralis, by having more scales around the midbody (104-107, =105.66) than S. boettgeri (79-104, Mean= 88.61), S. haenschi (57-64, Mean=60.50), and S. varius (74-88, Mean=82.35); and from S. humeralis by having the scales in the frontonasal region nearly equal in size to the scales in the occipitoparietal region, while in S. humeralis the scales on the frontonasal region are twice or three times longer than the scales on the occipitoparietal region.
ZooKeys | 2013
Pablo J. Venegas; Omar Torres-Carvajal; Vilma Duran; Kevin de Queiroz
Abstract We report the discovery of two sympatric new species of Enyalioides from a montane rainforest of the Río Huallaga basin in northeastern Peru. Among other characters, the first new species is distinguishable from other Enyalioides by the combination of the following characters: strongly keeled ventral scales, more than 37 longitudinal rows of dorsals in a transverse line between the dorsolateral crests at midbody, low vertebral crest on the neck with vertebrals on neck similar in size to those between hind limbs, projecting scales on body or limbs absent, 96 mm maximum SVL in both sexes, and caudals increasing in size posteriorly within each autotomic segment. The second new species differs from other species of Enyalioides in having strongly keeled ventral scales, scales posterior to the superciliaries forming a longitudinal row of strongly projecting scales across the lateral edge of the skull roof in adults of both sexes, 31 or fewer longitudinal rows of strongly keeled dorsals in a transverse line between the dorsolateral crests at midbody, vertebrals on neck more than five times the size of vertebrals between hind limbs in adult males, projecting scales on body or limbs absent, and caudals increasing in size posteriorly within each autotomic segment. We also present an updated molecular phylogenetic tree of hoplocercines including new samples of Enyalioides rudolfarndti, Enyalioides rubrigularis, both species described in this paper, as well as an updated identification key for species of Hoplocercinae.
ZooKeys | 2011
Germán Chávez; Karen Siu-Ting; Vilma Duran; Pablo J. Venegas
Abstract Two new species of lizards assigned to the genus Euspondylus from the montane forests of the Peruvian Andes in the Pasco Department (central Peru) and Ayacucho Department (southern Peru) both at elevations of 2550 and 3450 m, respectively, are described. The new species are distinguishable from all other Peruvian and Ecuadorian species of Euspondylus by a unique combination of morphometric, scalation and color pattern characteristics. Natural history data for the new species and for Euspondylus spinalis are also provided.