New species of beaked toad, Rhinella (Anura: Bufonidae), from the State of Bahia, Brazil

TAXONOMY AND NOMENCLATURE

New species of beaked toad, Rhinella (Anura: Bufonidae), from the State of Bahia, Brazil

Ulisses Caramaschi

Museu Nacional, Departamento de Vertebrados, Universidade Federal do Rio de Janeiro,. Quinta da Boa Vista, 20940-040 Rio de Janeiro, RJ, Brazil, E-mail: [e-mail]

ABSTRACT

A new species of beaked toad, Rhinella, is described from Itacaré (14°17'S, 38°60'W; 13 m altitude), State of Bahia, Northeastern Brazil. Rhinella skuki sp. nov. is related to R. boulengeri and distinguished by the size small (SVL 26.2 mm in male); head longer than wide; snout, viewed from above, long, narrow, spatulate, with lateral borders parallel and rounded tip; in profile, long, strongly acute; parotoid glands large, rounded; tympanum concealed; dorsum rugose, with rounded tubercles uniformly distributed; vocal sac and vocal slits absent; fingers slender, not webbed nor ridged; first finger hypertrophied, with a rounded nuptial pad on the inner surface; toes slender, slightly fringed; webbing absent; ground color of dorsal surfaces dark brownish gray with an interorbital bar and dorsolateral blotches clear brownish gray, leaving an apparent pattern of arrows on dorsum; venter and ventral surfaces of arms and thighs cream with diffuse gray stains and dots; gular region and chest dark brownish gray.

Key words: Amphibia; Northeastern Brazil; Rhinella skuki sp. nov.; Taxonomy.

The species originally or secondarily included in Rhamphophryne Trueb, 1971 [R. acrolopha Trueb, 1971, R. festae (Peracca, 1904), R. lindae Rivero & Castaño, 1990, R. macrorhina Trueb, 1971, R. nicefori (Cochran & Goin, 1970), R. rostrata (Noble, 1920), R. ruizi Grant, 2000, R. tenrec Lynch & Renjifo, 1990, and R. truebae Lynch & Renjifo, 1990)] occur in Northwestern South America and in Central America, ranging from Northern Peru, Ecuador, Colombia, to adjacent Panama, between 800-1300 m altitude (Frost 2011). The only exception is R. proboscidea (Boulenger, 1882), occurring in Eastern Brazil, in the states of Bahia and Minas Gerais, associated to the Atlantic Rain Forest, at altitudes between the sea level and 890 m (Izecksohn 1976, Feio et al. 2003). Chaparro et al. (2007a) transferred all species of the genera treated by Frost et al. (2006) as Rhinella Fitzinger, 1828 (which included Rhamphophryne) and Chaunus Wagler, 1828 into Rhinella. This action resulted in the secondary homonymy of Bufo (Oxyrhynchus) proboscideus Spix, 1824 (formerly Rhinella proboscidea) and Phryniscus proboscideus Boulenger, 1882 (formerly Rhamphophryne proboscidea). A new name, Rhinella boulengeri Chaparro, Pramuk, Gluesekamp & Frost, 2007, was proposed as replacement for the latter (Chaparro et al. 2007b).

In this paper, a new species of Rhinella related to R. boulengeri from the State of Bahia, Northeastern Brazil, is described.

MATERIAL AND METHODS

Examined specimens and data were obtained from the collections of the Museu Nacional, Rio de Janeiro, RJ, Brazil (MNRJ), Museu de Zoologia, Universidade Federal da Bahia, Salvador, BA, Brazil (UFBA), and Museu de Zoologia, Universidade Federal de Viçosa, MG, Brazil (MZUFV).

Measurements, in millimeters (mm), followed Napoli (2005): (SVL) snout-vent length, (HL) head length, (HW) head width, (IND) internarial distance, (END) eye to nostril distance, (ED) eye diameter, (UEW) upper eyelid width, (IOD) interorbital distance, (HAL) hand length, (THL) thigh length, (TL) tibia length, (FL) foot length.

TAXONOMY

Rhinella skuki sp. nov.

Figs 1-¹²

Holotype. Brazil: Bahia: Itacaré (14°17'S, 38°60'W; 13 m altitude), MNRJ 74619, adult male (Figs 1-2), 14 January 2006, Marco Antônio de Freitas leg.

Diagnosis. A species related to Rhinella boulengeri, characterized by: 1) size small (SVL 26.2 mm in male); 2) head longer than wide; 3) snout, viewed from above, long, narrow, spatulate, with parallel lateral borders and rounded tip; in profile, long, strongly acute; 4) parotoid glands large, rounded; 5) tympanum concealed; 6) dorsum rugose, with rounded tubercles uniformly distributed; 7) vocal sac and vocal slits absent; 8) fingers slender, not webbed nor ridged; first finger hypertrophied, with a rounded nuptial pad on the inner surface; 9) toes slender, slightly fringed; webbing absent; 10) ground color of dorsal surfaces dark brownish gray with an interorbital bar and dorsolateral blotches clear brownish gray, leaving an apparent pattern of arrows on dorsum; (11) venter and ventral surfaces of arms and thighs cream with diffuse gray stains and dots; gular region and chest dark brownish gray.

Comparisons with other species. Rhinella skuki sp. nov. is readily distinguished from R. boulengeri by the smaller size (SVL 26.2 mm in male of R. skuki sp. nov.; 39.2-46.4 mm in males of R. boulengeri), snout long, narrow, spatulate, with parallel lateral borders and rounded tip in dorsal view, and long, strongly acute, in lateral view (snout short, wide, approximately truncate in dorsal view, and only acute in lateral view in R. boulengeri; Figs 3-8), head longer than wide (wider than long in R. boulengeri), and dorsal tubercles large and uniformly distributed (dorsal tubercles small, numerous, densely distributed in R. boulengeri).

Description of holotype. Stout build (Figs 1-2); head slightly longer than wide, HW 94.4% of HL, HW 32.4% of SVL, HL 34.3% of SVL. Snout, viewed from above, long, narrow, spatulate, with parallel lateral borders and rounded tip (^{Fig. 9}); in lateral view, long, strongly acute (^{Fig. 10}); canthus rostralis distinct, slightly concave; loreal region vertical, slightly concave; dorsum of snout concave. Nostrils lateral, nearer to the tip of snout than to eyes (snout to nostril distance 84.6% of eye to nostril distance); internarial distance slightly larger than eye to nostril distance, slightly smaller than eye diameter, and equal to the interorbital distance. Eyes large, not prominent, lateral, slightly directed ahead; eye to nostril distance smaller than eye diameter and interorbital distance, and larger than the upper eyelid width. Upper eyelid width smaller than interorbital distance. Tympanum concealed. Upper eyelid, head, dorsal skin, and dorsal surface of arms and legs rugose, with rounded tubercles uniformly distributed. Cephalic crests absent. Dorsum rugose, with rounded tubercles uniformly distributed. Parotoid gland large, rounded; forearm and tibial glands absent. Flanks, ventral skin, and ventral surfaces of arms and legs with rounded tubercles uniformly distributed; gular region and chest barely rugose, with few tubercles. Vocal sac and vocal slits absent; choanae small, widely separated; tongue long, free, not notched behind. Arms robust, forearm and arm approximately equal, without dermal crests. Hand robust (^{Fig. 11}) with fingers slender, not webbed nor ridged, tips rounded, slightly expanded; fingers lengths I<II<IV<III; first finger hypertrophied, with a rounded nuptial pad on the inner surface; subarticular tubercles rounded, proximal tubercles more developed than distal ones; supernumerary tubercles absent; outer metacarpal tubercle large, elliptical, twice as long as wide; inner metacarpal tubercle large, rounded. Legs long, thigh and tibia lengths almost equal (THL 99.1% of TL; THL 40.4% of SVL; TL 40.8% of SVL); sum of tibia and thigh lengths 81.3% of SVL. Foot large (^{Fig. 12}), foot length smaller than tibia and thigh lengths, 35.5% of SVL. Toes slender, slightly fringed; toes lengths I<II<V<III<IV; toe tips rounded, slightly expanded; webbing absent; subarticular tubercles large, rounded; sole of foot with distinct, large rounded supernumerary tubercles; outer metatarsal tubercle small, rounded; inner metatarsal tubercle very large, elliptical, with the external border free; three rows of approximately aligned tubercles on the ventral surface of tarsus. Anal region not modified, rugose.

Measurements of holotype (mm): SVL 26.2; HL 9.0; HW 8.5; IND 3.0; END 2.6; ED 2.9; UEW 2.3; IOD 3.0; HAL 6.4; THL 10.6; TL 10.7; FL 9.3.

Color in preservative. Background color of dorsal surfaces dark brownish gray with an interorbital bar and dorsolateral blotches clear brownish gray, leaving an apparent pattern of arrows on dorsum; arms and hands clear brownish gray with dark brownish gray blotches; legs dark brownish gray with transversal clear brownish gray bars. Venter and ventral surfaces of arms and thighs cream with diffuse gray stains and dots; gular region and chest dark brownish gray; hands cream; tarsus and feet gray and toes cream.

Additional specimens examined. Rhinella boulengeri: Brasil, Bahia: Arataca, Fazenda Boa Sorte (MNRJ 26455); Catu (UFBA 10086-10087, 10551); Macarani (MZUFV 6001); Salvador, Rio Cururipe (MNRJ 2733-2734); Vera Cruz (UFBA 10108); Wenceslau Guimarães (UFBA 10470). Minas Gerais: Almenara, Fazenda Limoeiro (MZUFV 4134-4138, MZUFV 5929-5934).

Geographic distribution: Known from the type locality, in the municipality of Itacaré, state of Bahia, northeastern Brazil. This locality is within the general range of R. boulengeri, but apparently the latter has a more inland distribution than R. skuki (Fig. 13).

Etymology. The species is dedicated to our late friend and herpetologist Gabriel "Gabo"Skuk. He was born in Montevideo, Uruguay, on 01 January 1962, and graduated in Biological Sciences by the Universidad de La República Oriental del Uruguay, Facultad de Ciencias (1980-1986); obtained his Master in Zoology (1989-1994) and PhD in Zoology (1994-1999) by the Universidade de São Paulo, Brazil. Great collector and fine biological observer, he was a pleasant companion, always prompt to help any person that asked for, even if in prejudice of his own interests. He was a professor in the Universidade Federal de Alagoas, Maceió, State of Alagoas, Brazil. Enthusiast of diving and submarine hunting, he drowned and died at the Tabuba beach, in the municipality of Paripueira, about 30 km North of Maceió, on 19 March 2011, at 49 years age.

DISCUSSION

The extensively disjunct distribution among the Andean members of the former Rhamphophryne and the two species occurring in eastern Brazil is remarkable, but not unique (e.g., see distribution of species of the eleutherodactylid genus Adelophryne in Hoogmoed et al. 1994, and of the bufonid species included in the Rhinella margaritifera group in Caramaschi & Pombal 2006). However, apparently the closely related R. boulengeri and R. skuki constitute an independent evolutionary branch. All species of the former genus Rhamphophryne and the species of Rhinella sensu Frost et al. (2006) (i.e., species currently allocated to the R. margaritifera group) present characteristic dorsolateral rows of tubercles extending from the posterior margin of the head or parotoid gland posteriorly along the flanks to or near to the groin (Trueb 1971, Hoogmoed 1990); R. boulengeri and R. skuki lack this character. Additionally, all species of the former genus Rhamphophryne have webbed hand and foot and developed cephalic crests; however, R. boulengeri and R. skuki have free fingers and toes and no cranial crests. Rhinella acrolopha, R. festae, R. macrorhina, R. tenrec, and R. truebae present snout long and ventrally curved, R. nicefori, R. rostrata, and R. ruizi have a short and rounded snout, and R. lindae has an acuminate, more or less, triangular snout in dorsal view and protruding in lateral view (snout long, pointed, directed anteriorly in R. boulengeri and R. skuki); R. lindae and R. truebae have external tympanic membrane (absent in R. boulengeri and R. skuki), and R. rostrata have developed vocal slits (absent in R. skuki) (cf. Grant 2000, Lynch & Renjifo 1990, Rivero & Castaño 1990, Trueb 1971).

Rhinella skuki is currently known from one specimen (holotype), obtained in a locality in eastern State of Bahia, practically at the sea level. Intensive fieldwork in the region is needed to evaluate the actual distribution of this species, its population size, and conservation status.

ACKNOWLEDGEMENTS

We are grateful to Renato N. Feio (MZUFV) and Marcelo F. Napoli (UFBA) for allowing examining specimens under his care; to Roberta Richard Pinto for the help with the photographs; to Paulo Roberto Nascimento for the line drawings; and to Marcelo F. Napoli for the map. To the Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) for financial support.

LITERATURE CITED

Submitted: 22.XI.2011; Accepted: 23.V.2012.

Editorial responsibility: Ana Lúcia Prudente

• Caramaschi, U. & J.P. Pombal Jr. 2006. A new species of Rhinella Fitzinger, 1826 from the Atlantic Rain Forest, eastern Brazil (Amphibia, Anura, Bufonidae). Papéis Avulsos de Zoologia 46 (23): 251-259.
• Chaparro, J.C.; J.B. Pramuk & A.G. Gluesekamp. 2007a. A new species of arboreal Rhinella (Anura: Bufonidae) from cloud forest of Southeastern Peru. Herpetologica 63 (2): 203-212.
• Chaparro, J.C.; J.B. Pramuk; A.G. Gluesekamp & D.R. Frost. 2007b. Secondary homonymy of Bufo proboscideus Spix, 1824, with Phryniscus proboscideus Boulenger, 1882. Copeia 2007 (4): 1029.
• Feio, R.N.; B.V.S. Pimenta & D.L. Silvano. 2003. Rediscovery and biology of Rhamphophryne proboscidea (Boulenger, 1882) (Anura, Bufonidae). Amphibia-Reptilia 24: 108-112.
• Frost, D.R. 2011. Amphibian Species of the World: an Online Reference. Version 5.5 (31 January, 2011). Available online at: http://research.amnh.org/vz/herpetology/amphibia/American Museum of Natural History, New York, USA [Accessed: 10/XI/2011]
• Frost, D.R.; T. Grant; J. Faivovich; R.H. Bain; A. Haas; C.F.B. Haddad; R.O. De Sá; A. Channing; M. Wilkinson; S.C. Donnellan; C.J. Raxworthy; J.A. Campbell; B.L. Blotto; P. Moler; R.C. Drewes; R.A. Nussbaum; J.D. Lynch; D.M. Green & W.C. Wheeler. 2006. The amphibian tree of life. Bulletin of the American Museum of Natural History 297: 1-370.
• Grant, T. 2000 [1999]. Uma nueva especie de Rhamphophryne (Anura: Bufonidae) de La Cordillera Central de Colombia. Revista de la Academia Colombiana de Ciencias 23 (Supl.): 287-292.
• Hoogmoed, M.S. 1990. Biosystematics of South American Bufonidae, with special reference to the Bufo "typhonius"group, p. 113-123. In: G. Peters & R. Hutterer (Eds). Vertebrates in the Tropics. Bonn, Museum Alexander Koenig.
• Hoogmoed, M.S.; D.M. Borges & P. Cascon. 1994. Three new species of the genus Adelophryne (Amphibia: Anura: Leptodactylidae) from Northeastern Brazil, with remarks on the other species of the genus. Zoologische Mededelingen 68: 271-300.
• Izecksohn, E. 1976. O status sistemático de Phryniscus proboscideus Boulenger (Amphibia, Anura, Bufonidae). Revista Brasileira de Biologia 36 (2): 341-345.
• Lynch, J.D. & J.M. Renjifo. 1990. Two new toads (Bufonidae: Rhamphophryne) from the Northern Andes of Colombia. Journal of Herpetology 24 (4): 364-371.
• Napoli, M.F. 2005 A new species allied to Hyla circumdata (Anura: Hylidae) from Serra da Mantiqueira, Southeastern Brazil. Herpetologica 61 (1): 63-69.
• Rivero, J.A & C.J. Castaño. 1990. A new and peculiar species of Rhamphophryne (Amphibia: Bufonidae) from Antioquia, Colombia. Journal of Herpetology 24 (1): 1-5.
• Trueb, L. 1971. Phylogenetic relationships of certain neotropical toads with the description of a new genus (Anura: Bufonidae). Contributions in Science, Los Angeles County Museum 216: 1-40.

Publication Dates

• Publication in this collection
  20 Aug 2012
• Date of issue
  Aug 2012

History

• Received
  22 Nov 2011
• Accepted
  23 May 2012