ABSTRACT
Southern Amazonia is one of the less-explored regions by anuran taxonomists. We describe a small new species of snouted treefrog, genus Scinax, from this region, from a fluvial archipelago in the Juruena River, state of Mato Grosso, Brazil. The description is based on external morphology of adults and tadpoles, advertisement call and molecular data. The species is phylogenetically related to other snouted treefrogs of the Scinax cruentomma species group and shows the most southeastern distribution in Amazonia among its close relatives. It is distinguished from congeners mainly by its larger adult body size and bilobate vocal sac that reaches the level of the pectoral fold, a reddish-brown horizontal stripe on the iris, dark melanophores or blotches on the vocal sac and the throat of females, and the uniformly brown posterior portion of the thigh. The advertisement call comprises one pulsed note emitted at regular intervals, with a duration of 189-227 ms, 30-35 pulses/note and a dominant frequency of 2,250-2,344 Hz. The type locality is suffering several environmental impacts, including illegal mining, overfishing, unsustainable agriculture, uncontrolled logging and degradation associated with the construction of new hydroelectric dams. Further study of the biology and regional distribution of the new species is required to propose mitigation measures needed for its conservation.
Subject(s)
Anura , Rivers , Animals , Female , Brazil , Conservation of Natural Resources , FisheriesABSTRACT
[This corrects the article DOI: 10.1371/journal.pone.0229971.].
ABSTRACT
The Pristimantis genus (Anura: Craugastoridae) is the most diverse among all vertebrates with 531 described species. The highest diversity occurs in Ecuador (215 species), followed by Colombia (202), Peru (139), Venezuela (60), Brazil (30), Bolivia (17), Guyana (6) Suriname and French Guiana (5). The genus is divided into 11 species groups. Of these, the P. conspicillatus group (containing 34 species), distributed in extreme southeastern Costa Rica, Isla Taboga (Panama), northern South America (from Colombia to eastern Guyana), south Bolivia, and is the best represented in Brazil (16 species). The main characteristics of this group are the tympanic membrane and tympanic annulus distinct (except in P. johannesdei); dorsum smooth or shagreen; dorsal lateral fold present or absent; usually smooth belly, but may be weakly granular in some species; toe V slightly larger than the toe III. Most of the taxonomic inconsistencies in species of Pristimantis could be due to its much conserved morphology and the lack of comprehensive taxonomic evaluations. Thus, an ongoing challenge for taxonomists dealing with the Pristimantis genus is the ubiquitous abundance of cryptic species. In this context, accurate species delimitation should integrate evidences of morphological, molecular, bioacoustics and ecological data, among others. Based on an integrative taxonomy perspective, we utilize morphological, molecular (mtDNA) and bioacoustic evidence to describe four new species of the Pristimantis conspicillatus group from the eastern Amazon basin. Pristimantis giorgii sp. nov. is known from the Xingu/Tocantins interfluve and can be distinguished from the other Pristimantis species of the region by presenting discoidal fold, dorsolateral fold absent, vocalization composed of three to four notes and genetic distance of 7.7% (16S) and 14.8% (COI) from P. latro, the sister and sympatric species with respect P. giorgii sp. nov.. Pristimantis pictus sp. nov. is known to the northern Mato Grosso state, Brazil, and can be distinguished from the other species of Pristimantis by presenting the posterior surface of the thigh with light yellow patches on a brown background, also extending to the inguinal region, vocalization consisting of four to five notes and a genetic distance of 11.6% (16S) and 19.7% (COI) from P. pluvian sp. nov., which occurs in sympatry. Pristimantis pluvian sp. nov. is known to the northern Mato Grosso state, Brazil, and may be distinguished from the other Pristimantis species by having a posterior surface of the thigh reddish and vocalization composed of two notes. Pristimantis moa sp. nov. is known to the northern Tocantins state and southwestern Maranhão state. This species can be distinguished from the other Pristimantis species by possessing slightly perceptible canthal stripe, external thigh surface with dark yellow spots on brown background, vocalization consisting of three to five notes and genetic distance of 2.3-11.7 (16S) and 10.5-23.1 (COI) for the new Pristimantis species of this study.
Subject(s)
Animal Distribution , Anura/classification , Phylogeny , Animals , Anura/anatomy & histology , Anura/genetics , Brazil , Central America , South AmericaABSTRACT
The genus Pristimantis has the highest species diversity among all terrestrial vertebrates, with most species observed in the Andean region and the Guiana Shield. Even with the recent description of a new species, only P. latro, P. dundeei and P. zimmermanae occur in the south of the Amazon River. The lack of taxonomists specialized in the field leads to the propagation of dubious terminologies (e.g. Pristimantis sp1, Pristimantis sp2, P. aff. Fenestratus and P. gr. conspicillatus) or even misidentification of species, resulting in erroneous species distributions. In this study, we applied the Automatic Barcode Gap Discovery (ABGD) algorithm for the delimitation of candidate species and values of genetic distances using the mitochondrial marker Cytochrome Oxidase Subunit I (COI), proposed in the barcode methodology, where values greater than 10% are considered as indicative of different species. We found large genetic distances between P. latro and Pristimantis sp1 Unconfirmed Candidate Species - UCS1 (21%), and between P. altamazonicus and Pristimantis sp2 UCS2 (14%). The ABGD method recognized UCS1 and UCS2 as distinct species. Pristimantis sp. UCS1 and UCS2 in the east of the Brazilian Amazon are indicated as candidate species. We suggest greater sampling of Pristimantis sp. UCS1 and UCS2, integrating morphology and bioacoustics to solve the taxonomic status in the east of the Brazilian Amazon.
