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| Allobates tinae
Melo-Sampaio, De Oliveira & Prates, 2018
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Abstract
Limited knowledge about species diversity restricts inferences about biogeography and macroecology in Amazonia, where biodiversity documentation has become particularly pressing due to anthropogenic impacts. An emblematic example of poorly known Amazonian amphibian diversity is that of Allobates nurse frogs, in which species boundaries and ranges are unclear. Based on genetic, morphological and call data from samples collected in 14 poorly known sites in Brazil, we identify and describe a new, broadly distributed western Amazonian nurse frog. In the light of the genetic data, combined with examination of more than 400 museum specimens, we also assess the distribution and levels of phenotypic variation in poorly known species from Amazonian lowlands, namely A. flaviventris, A. gasconi, A. subfolionidificans, and A. trilineatus. Lastly, our morphological examinations point to inconsistencies and heterospecific samples in the type series of A. fuscellus, A. gasconi, and A. vanzolinius, as revealed by large variation in key traits. By improving knowledge about species ranges and identifications, we hope that this study will support biodiversity inventories and stimulate further investigations of understudied western Amazonian nurse frogs.
Keywords: Amazon, Amphibia, South America, Systematics, Taxonomy
Allobates tinae sp. nov.
Allobates sp. Grant et al., 2006: 299, fig. 73 (clades “Manaus 1, “PEG-M1”, and “Rio Ituxi”).
– Simões, 2016: 519, fig. 12H–I. – Santos et al., 2009: fig. S3A (clades “Small”, “sp. 1”, and “gasconi”).
Allobates aff. conspicuus Melo-Sampaio et al., 2013: 339.
Allobates flaviventris Melo-Sampaio et al., 2013: 338 (in part).
Allobates sp. Grant et al., 2017: S29, fig. 21 (clades “PEGM1”, “small”, “Rio Ituxi”, “Manaus 1” and “Castanho”).
Diagnosis: The new species is included in the genus Allobates on the basis of the phylogenetic results (Fig. 3) and overall similarity with congeners (Fig. 4–5). Allobates tinae sp. nov. is diagnosed by the following combination of characteristics: (i) snout rounded in lateral and dorsal views; (ii) a medium-sized species, mean SVL of males 15.2 mm (range 14.2–15.9 mm), mean SVL of females 15.8 mm (range 14.8–17.2 mm); (iii) dorsal surface of snout uniformly light brown, same color extending posteriorly until eye level; dorsum tan brown in life; (iv) skin texture of dorsum granular, flat small granules scattered from the level of the eyes to the urostyle region; (v) dark brown lateral stripe with well delimited upper and lower edges; (vi) pale dorsolateral stripe present in preserved specimens, conspicuous in life; (vii) oblique lateral stripe absent, pale cream spots scattered on inguinal region of the dark brown lateral stripe, reaching up to two thirds of it towards the forelimbs; (viii) iridescent white ventrolateral stripe conspicuous in live and preserved specimens, unbroken from tip of snout to inguinal region; (ix) bright paracloacal mark present, half-moon shaped; (x) sexual dimorphism in throat and chest coloration of live specimens (golden yellow in males, white in females); (xi) abdominal surfaces cream, reaching towards the flanks (xii) dorsal surface of legs uniform, without transversal dark stripes; (xiii) iris metallic gold, without a pupil ring; (xiv) vocal sac distinct, single, subgular; (xv) maxillary teeth present; (xvi) Finger III not swollen in males; (xvii) basal webbing present between Toes III and IV; (xviii) fringes absent on toes; (xix) diurnal habits, males calling in daytime; (xx) advertisement calls characterized by the emission of tonal notes ranging between 4,875–6,029 Hz.
Etymology The specific epithet honors Dr. Albertina Pimentel Lima, a professor at the Instituto Nacional de Pesquisas da Amazônia (INPA), for her extensive contributions to Al‑ lobates taxonomy. Dr. Lima has described or re-described with colleagues more than a dozen species of nurse frogs. Her work has inspired the first author to investigate Allobates taxonomy.
Distribution The new species is known from lowland western Amazonia in Brazil to the south of the Amazon River (Fig. 2) in the states of Acre, Amazonas and Rondônia. In its type locality (..., Amazonas), Allobates tinae sp. nov. is syntopic with A. gasconi and A. femoralis. To the south (e.g., ..., Acre), it co-occurs with A. hodli, A. subfolionidificans, and A. trilineatus. To the east (e.g., in the middle course of the Madeira River), A. tinae sp. nov. is sympatric with A. caeruleodactylus, A. flaviventris, A. grillisimilis, A. masniger, and A. nidicola (see Simões 2016).
Paulo R. Melo-Sampaio, Renan M. De Oliveira and Ivan Prates. 2018. A New Nurse Frog from Brazil (Aromobatidae: Allobates), with Data on the Distribution and Phenotypic Variation of Western Amazonian Species. South American Journal of Herpetology. 13(2); 131-149. DOI: 10.2994/SAJH-D-17-00098.1
Resumo: Um conhecimento limitado sobre a diversidade de espécies restringe inferências sobre biogeografia e macroecologia na Amazônia, onde documentar padrões de biodiversidade tornou-se particularmente urgente devido a impactos antropogênicos. Um exemplo emblemático de anfíbios amazônicos cuja diversidade é mal conhecida é o das rãs-cuidadoras do gênero Allobates, para as quais as distribuições e os limites entre espécies ainda não estão claros. Com base em dados genéticos, morfológicos e de vocalização de espécimes amostrados em 14 localidades pouco exploradas no Brasil, identificamos e descrevemos uma nova espécie de Allobates de ampla distribuição na Amazônia ocidental. À luz dos dados genéticos, em combinação com o exame de mais de 400 espécimes de museus, também examinamos a distribuição e a variação fenotípica em espécies pouco conhecidas das planícies amazônicas, nomeadamente A. flaviventris, A. gasconi, A. subfolionidificans e A. trilineatus. Por último, a análise de espécimes depositados em coleções zoológicas aponta para inconsistências e amostras heteroespecíficas na série tipo de A. fuscellus, A. gasconi e A. vanzolinius, como revelado por uma grande variação em caracteres-chave. Ao melhorar o conhecimento sobre as distribuições e identificações de espécies, esperamos que este estudo apoie inventários de biodiversidade e estimule novas investigações sobre as pouco conhecidas rãs-cuidadoras da Amazônia ocidental.
