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| Pristimantis guianensis Mônico, Ferrão, Chaparro, Fouquet & Lima, 2022 DOI: 10.3897/vz.72.e90435 |
Abstract
Pristimantis is already the most speciose genus among vertebrates, yet the current number of species remains largely underestimated. A member of the P. unistrigatus species group from the Guiana Shield has been historically misidentified as P. ockendeni, a species described from southern Peru. We combined mitochondrial (16S and COI) and nuclear (RAG1) loci, external morphology, skull osteology (μ-CT scan), vocalization (advertisement and courtship calls), geographic distribution and natural history data to differentiate the Guiana Shield populations from P. ockendeni, and describe them as a new species. The new species is crepuscular and nocturnal and inhabits the understory of unflooded (terra firme) forests in Brazil, Guyana and Suriname. It is phylogenetically related to P. ardalonychus, P. martiae and undescribed species from Brazilian Amazonia. The new species notably differs from P. ockendeni and its congeners in the P. unistrigatus species group occurring in the Guiana Shield by the combination of the following characters: absence of dentigerous processes of vomers, presence of vocal slits in males, body size (SVL 16.2–20.7 mm in males and 21.4–25.7 mm in females), advertisement call (call with 4–6 notes, call duration of 158–371 ms and dominant frequency of 3,466–4,521 Hz) and translucent groin coloration in life. To facilitate the recognition and description of cryptic species previously hidden under the name P. ockendeni, we provide an amended diagnosis of this taxon based on external morphology and advertisement call of specimens recently collected nearby the type locality and additional localities in southwestern Amazonia.
Keywords: Amazonia, Amphibia, Brachycephaloidea, integrative taxonomy, natural history, Terrarana
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| Males of Pristimantis guianensis sp. nov. in life. A Holotype INPA-H 43918 (SVL 17.7 mm); B Paratype MPEG 44188 (SVL 18.4 mm); C Paratopotype INPA-H 44250 (SVL 17.6 mm); D Paratype INPA-H 43939(SVL 17.6 mm); E Paratype MPEG 44185 (SVL 17.9 mm); F Paratopotype MPEG 44181 (SVL 17.8 mm); G Paratype INPA-H 43928 (SVL 17.9 mm); H Paratype INPA-H 43931 (SVL 17.7 mm); and I Paratype INPA-H 43926 (SVL 16.9 mm). Photographs: A.T. Mônico, except (C) E.D. Koch. |
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| Pristimantis guianensis sp. nov. natural history and breeding aspects. A Example of habitat used by the new species; B calling male (INPA-H 43942); C amplectant pair (female INPA-H 43943, male INPA-H 43944), from RFAD, Manaus, Amazonas; D suspended litter spawning about 1 m above the ground, the two clutches are at different stages (left, more developed; right, recent oviposition), from São João da Baliza municipality, Roraima, Brazil. Photographs: A.T. Mônico, except (B) I.Y. Fernandes. |
Pristimantis guianensis sp. nov.
Diagnosis: The new species is characterized by the following unique combination of characters: (1) dorsal skin shagreened, frequently with distinctly tubercles, with or without W-shaped on scapular region; (2) tympanum visible, tympanic membrane poorly differentiated, tympanum diameter 24–34% of eye diameter and annulus partially visible externally; supratympanic black band; (3) snout subacuminate to sub-rounded in dorsal view and rounded in in lateral profile, loreal region concave; (4) upper eyelid tubercles present; dark bar between the eyes, and three oblique black streaks below the eye; cranial crests absent; (5) nostril ovoid, slightly protuberant, directed laterally; interorbital distance 29–37% of head width; (6) tongue cordiform to ovoid; (7) absence of dentigerous processes of vomers (Fig. 7); (8) males with vocal slits, vocal sac median to subgular; nuptial pads absent; (9) Finger I slightly more shorter than II; finger discs ovoid to expanded (finger disc I less expanded compared to finger disc II, III and IV); (10) fingers without lateral fringes; (11) three to five enlarged ulnar tubercles, barely visible in fixed specimens (easily visible in individuals when in life); (12) tibia length 48–56% of SVL; (13) heel tubercle absent; tarsal tubercles aligned, ovoid to elliptical; tarsal fold short, barely visible; (14) thenar tubercle ovoid to elliptical; small palmar tubercle ill-defined, less than 30% of thenar tubercle; (15) toes without lateral fringes; rudiment of web absent; (16) toes I and II almost of the same size; toes discs ovoid (toe disc I and II, especially) to expanded (III, IV and V); (17) belly skin smooth to areolate, and ventral region of the femur externally areolate; (18) in life, translucent groin with small, scattered dark melanophores and absence of bright colored blotches or marks; (19) in life, iris is dichromatic, brown lower part and cream upper part; (20) SVL in adult males of 16.2–20.7 mm (n = 43) and in females of 21.4–25.7 mm (n = 13); and (21) advertisement call with average call duration of 232 ± 42 ms, inter-note interval of 44 ± 5 ms (68 ± 11 ms), minimum frequency of 2,827–3,695 Hz, maximum frequency of 4,333–6,688 Hz and dominant frequency of 3,466–4,521 Hz.
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Etymology: The specific epithet “guianensis” refers to the region of occurrence of the new species, widely distributed in the western Guiana region (the lowlands of the eastern part of the Guiana Shield).
Alexander Tamanini Mônico, Miquéias Ferrão, Juan Carlos Chaparro, Antoine Fouquet and Albertina Pimentel Lima. 2022. A New Species of Rain Frog (Anura: Strabomantidae: Pristimantis) from the Guiana Shield and Amended Diagnosis of P. ockendeni (Boulenger, 1912). Vertebrate Zoology. 72: 1035-1065. DOI: 10.3897/vz.72.e90435
