135 research outputs found
First record of the Amazonian tiny tree toad Amazophrynella minuta (Melin, 1941) (Anura: Bufonidae), for Venezuela
Amazophrynella minuta is a small toad widely distributed in the lowlands and midlands of the Amazon and Guiana regions. Herein we report the first record of this species from Venezuela based on a single specimen from Raudal de Danto, RĂo Cuao, northwestern Amazonas state. This record extends the distribution of the species more than 500 km from the closest known localities in Colombia and Brazi
Multiple Paternity in a Reintroduced Population of the Orinoco Crocodile (Crocodylus intermedius) at the El FrĂo Biological Station, Venezuela
The success of a reintroduction program is determined by the ability of individuals to reproduce and thrive. Hence, an understanding of the mating system and breeding strategies of reintroduced species can be critical to the success, evaluation and effective management of reintroduction programs. As one of the most threatened crocodile species in the world, the Orinoco crocodile (Crocodylus intermedius) has been reduced to only a few wild populations in the Llanos of Venezuela and Colombia. One of these populations was founded by reintroduction at Caño Macanillal and La Ramera lagoon within the El FrĂo Biological Station, Venezuela. Twenty egg clutches of C. intermedius were collected at the El FrĂo Biological Station for incubation in the lab and release of juveniles after one year. Analyzing 17 polymorphic microsatellite loci from 335 hatchlings we found multiple paternity in C. intermedius, with half of the 20 clutches fathered by two or three males. Sixteen mothers and 14 fathers were inferred by reconstruction of multilocus parental genotypes. Our findings showed skewed paternal contributions to multiple-sired clutches in four of the clutches (40%), leading to an overall unequal contribution of offspring among fathers with six of the 14 inferred males fathering 90% of the total offspring, and three of those six males fathering more than 70% of the total offspring. Our results provide the first evidence of multiple paternity occurring in the Orinoco crocodile and confirm the success of reintroduction efforts of this critically endangered species in the El FrĂo Biological Station, Venezuela
Revision of Proctoporus bolivianus Werner.
31 pages, 1 unnumbered page : illustrations (some color), map ; 26 cm.The genus Proctoporus comprises seven montane species distributed across the Central Andes of Peru, Bolivia, and northern Argentina. Within this genus, the extensive morphological variation observed in populations traditionally assigned to Proctoporus bolivianus suggested the presence of additional species. Using a combination of morphological character differences and a phylogenetic hypothesis based on mitochondrial (12S, 16S, and ND4) and nuclear (c-mos) DNA sequences, we find P. bolivianus to be composed of six distinct lineages. Among these, we name and describe herein Proctoporus carabaya, P. iridescens, and P. kiziriani and we resurrect the name Proctoporus lacertus. The remaining two lineages are also considered unnamed species and are referred herein as confirmed candidate species (CCS), which we refrain from naming due to lack of appropriate material. The new species named herein are found in the departments of Cusco and Puno, Peru, and are distinguishable from all other species of Proctoporus by unique combinations of morphometric, pholidosis, and color-pattern characteristics. A neotype of P. bolivianus is designated
Amphibians in Zootaxa: 20 years documenting the global diversity of frogs, salamanders, and caecilians
Zootaxa is a mega-journal that since its inception, 20 years ago, has contributed to the documentation of the planet?s biodiversity. Its role concerning terrestrial vertebrates has been crucial especially for amphibians, which are the most threatened class of vertebrates. As current editors of the Amphibia section, we reviewed the state of knowledge of taxonomic publications on amphibians over the last two decades (from 2001 to 2020). Our review reveals that 2,533 frogs, 259 salamanders, and 55 caecilians have been named in these 20 years, mainly in the tropical regions of South America, Asia, and Africa. More than half (57%) of these species descriptions were published in only 10 journals. At least 827 species of the new amphibians (29% of the total) were described in Zootaxa. This mega-journal has served also as a place of publication for monographs and systematic reviews, in addition to short articles documenting the vocalizations of anurans and the morphology of embryos and larvae. Its efficient evaluation process, the freedom of manuscript length, including full-color figures, and free of cost for the authors, has made Zootaxa a favorite for amphibian researchers. In an era of accelerating rates of biodiversity loss, documenting, describing, naming, and proposing evolutionary scenarios for species is, more than ever, an urgent task.Fil: Rivera Correa, Mauricio. Universidad de Antioquia; ColombiaFil: Baldo, Juan Diego. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Nordeste. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Posadas | Universidad Nacional de Misiones. Instituto de BiologĂa Subtropical. Instituto de BiologĂa Subtropical - Nodo Posadas; ArgentinaFil: Vera Candioti, MarĂa Florencia. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico - Tucumán. Unidad Ejecutora Lillo; ArgentinaFil: Goyannes Dill Orrico, Victor. Universidade Estadual de Santa Cruz; BrasilFil: Blackburn, David C.. University Of Florida. Florida Museum Of History; Estados UnidosFil: Castroviejo Fisher, Santiago. Pontificia Universidade CatĂłlica do Rio Grande do Sul; BrasilFil: Chan, Kin Onn. National University of Singapore; SingapurFil: Gambale, Priscilla. Universidade Federal de Goiás; BrasilFil: Gower, David J.. Natural History Museum; Reino UnidoFil: Quah, Evan S. H.. National University of Singapore; SingapurFil: Rowley, Jodi J. L.. University of New South Wales; AustraliaFil: Twomey, Evan. Goethe Universitat Frankfurt; AlemaniaFil: Vences, Miguel. Technische Universitat Carolo Wilhelmina Zu Braunschweig.; Alemani
Species diversity and biogeography of an ancient frog clade from the Guiana Shield (Anura: Microhylidae: Adelastes, Otophryne, Synapturanus) exhibiting spectacular phenotypic diversification
The outstanding biodiversity of the Guiana Shield has raised many questions about its origins and evolution. Frogs
of the genera Adelastes, Otophryne and Synapturanus form an ancient lineage distributed mostly across this region.
These genera display strikingly disparate morphologies and life-history traits. Notably, Synapturanus is conspicuously
adapted to fossoriality and is the only genus within this group to have dispersed further into Amazonia. Moreover,
morphological differences among Synapturanus species suggest different degrees of fossoriality that might be
linked to their biogeographical history. Through integrative analysis of genetic, morphometric and acoustic data, we
delimited 25 species in this clade, representing a fourfold increase. We found that the entire clade started to diversify
~55 Mya and Synapturanus ~30 Mya. Members of this genus probably dispersed three times out of the Guiana
Shield both before and after the Pebas system, a wetland ecosystem occupying most of Western Amazonia during the
Miocene. Using a three-dimensional osteological dataset, we characterized a high morphological disparity across the
three genera. Within Synapturanus, we further characterized distinct phenotypes that emerged concomitantly with
dispersals during the Miocene and possibly represent adaptations to different habitats, such as soils with different
physical properties.Peer reviewe
Vanishing native American dog lineages
<p>Abstract</p> <p>Background</p> <p>Dogs were an important element in many native American cultures at the time Europeans arrived. Although previous ancient DNA studies revealed the existence of unique native American mitochondrial sequences, these have not been found in modern dogs, mainly purebred, studied so far.</p> <p>Results</p> <p>We identified many previously undescribed mitochondrial control region sequences in 400 dogs from rural and isolated areas as well as street dogs from across the Americas. However, sequences of native American origin proved to be exceedingly rare, and we estimate that the native population contributed only a minor fraction of the gene pool that constitutes the modern population.</p> <p>Conclusions</p> <p>The high number of previously unidentified haplotypes in our sample suggests that a lot of unsampled genetic variation exists in non-breed dogs. Our results also suggest that the arrival of European colonists to the Americas may have led to an extensive replacement of the native American dog population by the dogs of the invaders.</p
Evolution in the Genus Rhinella: A Total Evidence Phylogenetic Analysis of Neotropical True Toads (Anura: Bufonidae)
True toads of the genus Rhinella are among the most common and diverse group of Neotropical anurans. These toads are widely distributed throughout South America, inhabiting a great diversity of environments and ecoregions. Currently, however, the genus is defined solely on the basis of molecular characters, and it lacks a proper diagnosis. Although some phenetic species groups have traditionally been recognized within Rhinella, the monophyly of some of them have been rejected in previous phylogenetic analyses, and many species remain unassigned to these poorly defined groups. Additionally, the identity and taxonomy of several species are problematic and hinder the specific recognition and description of undescribed taxa. In this work, we first perform phylogenetic analyses of separate mitochondrial and nuclear datasets to test the possible occurrence of hybridiza-tion and/or genetic introgression in the genus. The comparative analysis of both datasets revealed unidirectional mitochondrial introgressions of an unknown parental species into R . horribilis (“ghost introgression”) and of R . dorbignyi into R . bernardoi; therefore, the mitochondrial and nuclear data-sets of these species were considered separately in subsequent analyses. We performed total-evidence phylogenetic analyses that included revised molecular (four mitochondrial and five nuclear genes) and phenotypic (90 characters) datasets for 83 nominal species of Rhinella, plus several undescribed and problematic species and multiple outgroups. Results demonstrate that Rhinella was nonmono-phyletic due to the position of R . ceratophrys, which was recovered as the sister taxon of Rhaebo nasicus with strong support. Among our outgroups, the strongly supported Anaxyrus + Incilius is the sister clade of all other species of Rhinella. Once R . ceratophrys is excluded, the genus Rhinellais monophyletic, well supported, and composed of two major clades. One of these is moderately supported and includes species of the former R . spinulosa Group (including R . gallardoi); the mono-phyletic R . granulosa, R . crucifer, and R . marina Groups; and a clade composed of the mitochondrial sequences of R . horribilis. The other major clade is strongly supported and composed of all the spe-cies from the non-monophyletic R . veraguensis and R . margaritifera Groups, the former R . acrolophaGroup, and R . sternosignata. Consistent with these results, we define eight species groups of Rhinella that are mostly diagnosed by phenotypic synapomorphies in addition to a combination of morpho-logical character states. Rhinella sternosignata is the only species that remains unassigned to any group. We also synonymize nine species, treat three former subspecies as full species, and suggest that 15 lineages represent putative undescribed species. Lastly, we discuss the apparently frequent occurrence of hybridization, deep mitochondrial divergence, and “ghost introgression”; the incomplete phenotypic evidence (including putative character systems that could be used for future phy-logenetic analyses); and the validity of the known fossil record of Rhinella as a source of calibration points for divergence dating analyses.Peer reviewe
Species Limits, and Evolutionary History of Glassfrogs
Recognizing the mechanisms of speciation and the limits of species is essential to understand the origin of biodiversity and how to conserve it. The general aims of my investigations during my doctoral studies were two-fold: to study evolutionary patterns and processes, and to provide specific and superspecific taxonomic classifications that try to reflect evolutionary history. I have focused my research on anurans in their biodiversity hotspot, the American Tropics. I have used morphological, behavioral (mating calls), and genetic (DNA sequences) characters to study species boundaries between frogs of the genus Pristimantis and the family Centrolenidae (glassfrogs). The results show that the exclusive use of single lines of evidence or the application of arbitrary thresholds impair and bias our ability to recognize new species and limit the possibility to understand evolutionary processes. Only an integrative approach combining every source of evidence provides the necessary feedback to discover all species and test their identity by comparing independent sets of data. This approach further allows identifying those species that probably represent stable comparative units (well supported species hypotheses) and to flag taxa that require further assessment. Phylogenetic reconstructions based on seven nuclear and mitochondrial genes for about 100 species of glassfrogs revealed that previous hypotheses of relationships were mislead by rampant convergent evolution at the phenotypic level. None of the previously suggested classifications fit with the reconstructed evolutionary history. Consequently, we proposed a new classification consistent with this phylogeny. I also studied the tempo and mode of diversification among glassfrogs. Based on sequences from ten genes in 87 species, I estimated species divergence times, age-range correlation between sister species, and reconstructed ancestral areas and dispersal/vicariance events. The results revealed a complex model of diversification where geographical isolation seems to be the dominant scenario for speciation and only clades of altitudinal generalists have been able to spread across the Neotropical rainforests
Resurrection of hyalinobatrachium orocostale and notes on the hyalinobatrachium orientale species complex (Anura: Centrolenidae)
Hyalinobatrachium orientale has a complex taxonomic history suggesting that more than one species could be under this name. In this review, we try to clarify the current taxonomic status of this species by means of morphological, bioacoustic, and mitochondrial DNA sequence comparisons of specimens from Tobago Island and the Venezuelan Cordillera de la Costa (Oriental Sector, Cordillera del Litoral and Cordillera del Interior). Our data support the resurrection of Hyalinobatrachium orocostale, restricted to the Cordillera del Interior. Additionally, specimens from Cordillera del Litoral and Oriental Sector do not form a monophyletic group; hence, we define as Hyalinobatrachium sp. the populations from Cordillera del Litoral and H. orientale sensu stricto the populations from the Oriental Sector. Preliminary bioacoustic and morphological analyses indicate that the populations from Tobago are conspecific with Hyalinobatrachium orientale sensu stricto. © 2008 by The Herpetologists' League, Inc.Peer Reviewe
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