New Species of Leaf-litter Toad of the Rhinella margaritifera Species Group (Anura: Bufonidae) from Amazonia
We describe through integrative taxonomy a new Amazonian species of leaf-litter toad of the Rhinella margaritifera species group. The new species inhabits open lowland forest in southwest Amazonia in Brazil, Peru, and Bolivia. It is closely related to a Bolivian species tentatively identified as Rhinella cf. paraguayensis. Both the new species and R. paraguayensis share an uncommon breeding strategy among their Amazonian congeners: each breeds in moderate to large rivers instead of small streams or ponds formed by rainwater. The new species is easily differentiated from other members of the R. margaritifera species group by having a strongly developed bony protrusion at the angle of the jaw, a snout–vent length of 63.4–84.7 mm in females and 56.3–72.3 mm in males, well-developed supratympanic crests with the proximal portion shorter than the parotoid gland in lateral view, a divided distal subarticular tubercle on finger III, and multinoted calls composed of groups of 7–9 pulsed notes and a dominant frequency of 1,012–1,163 Hz. Recent studies have shown that the upper Madeira Basin harbors a megadiverse fauna of anurans, including several candidate species. This is the first member of the R. margaritifera species group to be described from this region in recent years, and at least two additional unnamed species await formal description.
Phylogeny of species of the Rhinella margaritifera species group based on one nuclear and three mitochondrial genes (2,997 bp) and reconstructed through Bayesian inference. Posterior probabilities above 0.80 are shown close to nodes and those greater than or equal to 0.95 are represented with an asterisk. Scale bar represents substitutions/site. Photographs by Santiago Ron, bioweb.bio (R. dapsilis, R. margaritifera), Anthony S. Ferreira (R. proboscidea) and Albertina P. Lima (Rhinella exostosica, new species). See Data Accessibility for tree file.
Dorsal (A) and ventral (B) views of the male holotype of Rhinella exostosica, new species, INPAH 41323, SVL 68.7 mm.
Dorsolateral (A) and lateral (B) views of the head, and ventral views of the hand (C) and foot (D) of the male holotype of Rhinella exostosica, new species, INPAH 41323. Scale bars, 5 mm.
Lateral and dorsolateral views of the head of Rhinella exostosica, new species (A–D), R. martyi (E, F), R. paraguayensis (G), and R. margaritifera (H). (A, B) Male holotype, INPAH 41323, SVL 68.7 mm. (C, D) Female, INPAH 41320, SVL 77.1 mm. (E, F) Female holotype, MNHN 2006.2601, SVL 66.5 mm. (G) Male holotype, UFMT 7430, SVL 50.4 mm. (H) Holotype, ZISP 257.1. Photographs by Miquéias Ferrão (A–D), Fréderic Braux, MNHN (E, F), Robson Ávila (G), and Konstantin D. Milto (H).
Dorsolateral (above) and dorsal (below) views of Rhinella exostosica, new species (A, B) and R. aff. margaritifera (C, D) from the upper Madeira River, municipality of Porto Velho, Rondônia, Brazil. (A) Adult female, INPAH 41322. (B) Adult male, INPAH 41321. (C) Adult female, INPAH 41333. (D) Adult male, INPAH 41334. Localities: A, B, Jací Direito Sampling Module; C, D, west bank of the upper Madeira River. Photographs by Albertina P. Lima.
Coloration in life of the adult male holotype of Rhinella exostosica, new species, INPAH 41323 (field number APL 19973). Dorsolateral (A) and ventral (B) views. Photographs by Albertina P. Lima.
Variation in dorsal coloration of preserved Rhinella exostosica, new species, from Brazil. (A) Adult female, INPAH 41320, SVL 77.1 mm. (B) Adult male, INPAH 41321, SVL 56.7 mm. (C) Adult male, INPAH 41327, SVL 84.4 mm. (D) Adult male, INPAH 41313, SVL 72.3 mm. (E) Adult female, INPAH 41312, SVL 84.2 mm. (F) Adult female, INPAH 41329, SVL 72.1 mm.
Variation in ventral coloration of preserved Rhinella exostosica, new species. (A) Adult female, INPAH 41314, SVL 83.4 mm. (B) Adult female, INPAH 41329, SVL 72.1 mm. (C) Adult female, INPAH 41327, SVL 84.4 mm. (D) Adult female, INPAH 41322, SVL 68.7 mm.
Color variation in life of Rhinella exostosica, new species, from Brazil (A–D), Peru (E), and Bolivia (F). (A) Adult females: INPAH 41320 (above), SVL 77.1 mm; INPAH 41322 (below), SVL 68.7 mm; (B) Adult female, INPAH 41318, SVL 79.1 mm. (C) Adult female, INPAH 41322. (D) Adult female, INPAH 41318. (E) Subadult, NMP6V 74915. (F) Adult male, CBF 5800. Photographs by Albertina P. Lima (A–D) and Jiří Moravec (E–F).
Advertisement calls of Rhinella exostosica, new species (A–C), R. paraguayensis (D–E), and R. martyi (F–G). (A) Oscillogram of a series of eight-note calls of R. exostosica, new species. Detailed views of two (B) and one (C) calls of R. exostosica, new species. Detailed views of two (D) and one (E) calls of R. paraguayensis. Detailed views of two (F) and one (G) calls of R. martyi. Recordings: (A–C) INPAH 41331, Três Praias Camp, east bank of the Jací-Paraná River (affluent of the east bank of the Madeira River), Porto Velho, Rondônia, Brazil; (D–E) UFMT 2112, east bank of the Sepotuba River, Caceres, Mato Grosso, Brazil; (F–G) MNHN 2001.2006, Brownsberg Nature Park, Brokopondo district, Suriname.
Geographic distribution of Rhinella exostosica, new species (stars, circles, and squares) and Rhinella aff. margaritifera BRA (triangles). Localities: 1, type locality of R. exostosica, new species, Jací Direito Sampling Module; 2, Três Praias Camp; 3, Jací Novo Sampling Module; 4, Morrinhos Sampling Module; 5, Riberalta; 6, Bolpebra; 7, Puerto Maldonado; 8, Masisea.
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