Osteocephalus vasquezi Venegas, García-Ayachi, Toral, Malqui & Ron, 2023
- Dataset
- GBIF Backbone Taxonomy
- Rank
- SPECIES
- Published in
- Venegas, Pablo J., Garcia-Ayachi, Luis A., Toral, Eduardo, Malqui, Jose, Ron, Santiago R. (2023): A new species of spiny-backed tree frog, genus Osteocephalus (Anura, Hylidae), from the Yanachaga Chemillen National Park in central Peru. Evolutionary Systematics 7 (2): 237-251, DOI: http://dx.doi.org/10.3897/evolsyst.7.102360, URL: http://dx.doi.org/10.3897/evolsyst.7.102360
Classification
- kingdom
- Animalia
- phylum
- Chordata
- class
- Amphibia
- order
- Anura
- family
- Hylidae
- genus
- Osteocephalus
- species
- Osteocephalus vasquezi
description
Description of holotype. Adult male (Figs 4, 5), 51.4 mm SVL, head length 15.5 mm, head width 15.5 mm, eye diameter 5.3 mm, tympanum diameter 3.1 mm, femur length 23.7 mm, tibia length 28.0 mm, foot length 22.3 mm. Head narrower than body; snout truncate in lateral and dorsal views; canthus rostralis distinct and rounded; loreal region concave; internarial area depressed; nostrils slightly protuberant, directed laterally; interorbital area flat, with scattered small tubercles, lateral margins of the frontoparietals inconspicuous through skin; eye strongly protuberant; tympanic membrane evident, slightly wider than high, separated from eye by ca. 93 % of its diameter; tympanic annulus distinct. Tongue cordiform, widely attached to floor of mouth; vomerine odontophores angular, adjacent medially, posteromedial to choanae, bearing 9 and 8 (left / right) vomerine teeth; choanae with capsular shape, oblique; deflated vocal sacs distinct above the arms and below the ears. Axillary membrane present, reaching half the arm length; ulnar tubercles absent; relative length of fingers I <II <IV <III (Fig. 4); fingers bearing oval discs, that of Finger III about two thirds of tympanum diameter; subarticular tubercles prominent, round to ovoid except for slightly bifid distal subarticular tubercle of Finger IV; supernumerary tubercles present, distinct; palmar tubercle elongated; prepollical tubercle protuberant, elliptical; prepollex present; dark brown, keratinous nuptial excrescences covering inner surface of prepollex up to the intercalary cartilage of thumb; webbing basal between fingers I and II; webbing formula of fingers II 2 -- 3 III 3 -- 21 / 2 IV (Fig. 4). Small tubercles on tibiotarsal articulation; dorsal surface of tarsus covered by scattered minute keratinized conical tubercles, more abundant on outer edge; small tubercles scattered along ventrolateral edge of foot; toes bearing discs slightly wider than long, smaller than those of fingers; relative length of toes I <II <V <III <IV; outer metatarsal tubercle ill defined, small, round; inner metatarsal tubercle larger, ovoid; subarticular tubercles single, round, protuberant; supernumerary tubercles restricted to the soles; webbing formula of toes I 1 - 1 + II 1 - 1 + III 1 - 1 + IV 1 + - 1 V (Fig. 4). Skin on dorsum, head, and dorsal surfaces of hindlimbs shagreen, covered by conical tubercles with keratinized tips, tubercles minute on head and limbs; skin on flanks weakly areolate; skin on venter granular; skin on ventral surfaces of head smooth, on those of thighs smooth on the anterior half and granular on the posterior half, smooth on shanks. Cloacal opening directed posteriorly at upper level of thighs; short simple cloacal sheath covering cloacal opening; round tubercles around vent and on posterior surface of proximal third of thighs.
description
Figs 2, 4, 5, 6 A-D
diagnosis
Diagnosis. Osteocephalus vasquezi sp. nov. is most similar to O. mimeticus and O. aff. mimeticus (see Ortiz et al. 2022). Both species are similar in having dark irises with golden marks (see Fig. 2 A-F, 3 E-H). However, the new species can be distinguished from O. mimeticus in having a cream or creamy-tan venter with a well-defined pattern of brown chocolate blotches and flecks (venter cream, tan, or brown without marks in O. mimeticus). Additionally, adult males of Osteocephalus mimeticus are larger than those of O. vasquezi sp. nov. with non-overlapping ranges [SVL in O. mimeticus 58.2 - 67.5 mm, mean = 63.4 (n = 7), versus 40.9 - 52.9 mm, mean = 47.9 (n = 13)]. Furthermore, the tadpoles of O. vasquezi are strikingly different from the tadpoles of O. mimeticus (see Fig. 6) (state of characters between parenthesis) by having: truncate snout in dorsal view (rounded), nostrils oriented dorsolaterally closer to the eyes (nostrils oriented laterally and closer to the end of snout), fins at the posterior third of tail conspicuously narrower (gently narrower), and a higher number of lower labial tooth rows LTRF = 3 (3) / 9 (LTRF = 2 (2) / 6). Other species similar to Osteocephalus vasquezi sp. nov. are O. festae and O. verruciger (Fig. 3), both species of the Osteocephalus buckleyi group have predominantly dark irises, tuberculate dorsal skin, and brown dorsal coloration. Although some O. festae and O. verruciger share with O. vasquezi sp. nov. a cream or brownish-cream venter with dark brown chocolate marks, they differ from O. vasquezi sp. nov. in having a dark brown iris without bright marks and areolate flanks (iris dark brown with golden vermiculations or flecks, and smooth to weakly areolate in the anterior third of the flank in O. vasquezi sp. nov.). Additionally, in O. festae and O. mimeticus the subocular mark is usually conspicuous, while in the new species it is faint. Osteocephalus mutabor, O. omega, and O. sangay Chasiluisa, Caminer, Varela-Jaramillo & Ron, 2020, from the O. buckleyi group, also have brown dorsal coloration. However, in life, irises of O. mutabor and O. sangay are bronze with irregular black reticulations and in O. omega are golden yellow, whereas in the new species the irises are dark brown with golden vermiculations or flecks. Osteocephalus mutabor also can be readily distinguished by having a dorsal pattern of distinctive transversal stripes (absent in O. vasquezi sp. nov.) and lacking dark blotches or flecks on the ventral surface. Additionally, metamorphs and juveniles of O. mutabor have green dorsal coloration (black with golden marks in O. vasquezi sp. nov.). Females of O. sangay have scattered tubercles on dorsum, while females of O. vasquezi sp. nov. have the skin of dorsum smooth. Although O. sangay also has cream or tan venter with dark brown dots, the new species can be distinguished by its distinctive pattern of white or brown irregular blotches or vermiculations on the throat. The ventral coloration of Osteocephalus vasquezi sp. nov. is shared by some individuals of O. buckleyi Boulenger, 1882, O. cabrerai, O. camufatus, O. cannatellai Ron, Venegas, Toral, Read, Ortiz & Manzano, 2012, Osteocephalus duellmani, O. germani Ron, Venegas, Toral, Read, Ortiz & Manzano, 2012, O. helenae Ruthven, 1919, and O. vilmae Ron, Venegas, Toral, Read, Ortiz & Manzano, 2012. However, the new species can be easily distinguished, in life, in having a dark brown iris with golden vermiculations or flecks (iris varies from cream to golden or reddish golden and yellow with or without irregular reticulations in the afore listed species, except by O. duellmani due to its coloration in life is unknown). Furthermore, O. buckleyi, O. cabrerai, O. camufatus, O. cannatellai, O. helenae, and O. vilmae differ from O. vasquezi sp. nov. in having prominent tarsal tubercles (indistinct or absent in the new species). Osteocephalus cabrerai also has distinct tubercles on the lower jaw and a fringe in the outer edge of Finger IV, both characters absent in O. vasquezi sp. nov. The poorly known O. duellmani and O. germani have the skin on flanks coarsely areolate or areolate, respectively, and in O. vasquezi sp. nov. only weakly areolate in the anterior third of the flank, or completely smooth. Furthermore, O. duellmani differs from O. vasquezi sp. nov. in having the dorsum shagreen (tuberculate in the new species) and a conspicuous light subocular mark (faint in O. vasquezi sp. nov.). In O. germani the throat is cream with faint brown flecks, while in the new species is cream with brown blotches or brown with cream vermiculations. Predominantly dark brown irises are also present in O. alboguttatus Boulenger, 1882, O. heyeri Lynch, 2002, O. melanops, and O. subtilis Martins & Cardoso, 1987. Osteocephalus heyeri and O. alboguttatus can be easily distinguished from the new species by having brown flanks with scattered white blotches (flanks whitish cream or brownish cream with dark brown blotches and vermiculations in O. vasquezi sp. nov.). Osteocephalus subtilis differs from O. vasquezi sp. nov. in having the armpits, groins, anterior and posterior surfaces of thighs, and shanks blue, and the iris dark brown without bright marks. Osteocephalus melanops has a cream to white venter, while in the new species it is cream or creamy-tan with brown chocolate blotches and flecks. Osteocephalus oophagus, and O. taurinus can be easily distinguished from O. vasquezi sp. nov. in having bronze to golden irises (clear in preservative) with black lines radiating from the pupil. Furthermore, Osteocephalus taurinus differs from O. vasquezi sp. nov. in having dermal roofing bones of the skull exposed (not exposed in the new species). Osteocephalus leprieurii, and O. yasuni Ron & Pramuk, 1999 can be distinguished by their golden to golden brown irises with fine irregular dark venations and a broad dark brown horizontal midline. Osteocephalus yasuni also can be distinguished from O. vasquezi sp. nov. by its ventral coloration (from yellow to creamy-yellow in O. yasuni vs. cream or brownish-cream with chocolate-brown blotches and flecks in O. vasquezi sp. nov.) and the color of bones (white in O. yasuni and green in O. vasquezi sp. nov.). Additionally, O. leprieurii and O. yasuni breed in ponds and flooded areas (Jungfer et al. 2013), while the new species breeds in torrential streams. Osteocephalus castaneicola Moravec, Aparicio, Guerrero-Reinhard, Calderon, Jungfer & Gvozdik, 2009, O. deridens Jungfer, Ron, Seipp & Almendariz, 2000, O. fuscifacies Jungfer, Ron, Seipp & Almendariz, 2000, O. leoniae Jungfer & Lehr, 2001, O. planiceps Cope, 1874, and O. vilarsi differ from O. vasquezi sp. nov. (characters in parentheses) in having vocal sac single and subgular (vocal sacs paired, located above the arm and below the ear), dorsal skin not sexually dimorphic and more or less smooth in both sexes, except in O. planiceps and O. vilarsi (dorsal skin sexually dimorphic, strongly tuberculate in males and smooth in females), and breeding in phytotelmata, such as leaf axils, fruit capsules, bamboo and tree holes (Jungfer et al. 2013; Ferrao et al. 2019) (breeding in torrential streams). Additionally, the dark brown iris with golden vermiculation or flecks in O. vasquezi sp. nov. differs from the iris of all species in the O. planiceps group. Irises are golden to bronze with fine dark reticulate or black lines radiating from the pupil in O. castaneicola, O. leoniae, O. deridens, O. fuscifacies, O. planiceps, and O. vilarsi. Of the 29 species of Osteocephalus (Frost 2022) known to the date, only the larvae of six species have been formally described (i. e., O. cabrerai, O. festae, O. mimeticus, O. oophagus, O. taurinus and O. vilarsi) (Trueb and Duellman 1970; Henle 1981; Hero 1990; Schiesari et al. 1996; Ron et al. 2010; Ferrao et al. 2019). The tadpoles of O. vasquezi sp. nov. differ from its congeners by the following characters: truncate snout in dorsal view (except for O. oophagus, in the rest of species it is rounded), nostrils oriented dorsolaterally closer to the eyes than the end of snout (nostrils oriented laterally in the rest of species, closer to the end of snout in O. cabrerai, O. mimeticus, and O. vilarsi, and intermediate in O. taurinus and O. verruciger), fins at the posterior third of tail conspicuously narrower (except for O. festae, in the other species fins are gently narrower). Furthermore, O. vasquezi sp. nov. has a higher number of lower labial tooth rows: LTRF = 3 (3) / 9 vs. LTRF = 2 (2) / 6 (1) in O. cabrerai, 4 - 5 / 7 in O. festae, 2 (2) / 6 in O. mimeticus, 2 (2) / 6 in O. oophagus and 2 (2) / 3 - 7 (1) in O. taurinus, 2 (2) / 5 - 6 (1) in O. vilarsi, and 2 (2) / 5 (1) in O. verruciger.
distribution
Distribution and natural history. Osteocephalus vasquezi sp. nov. is only known from the type locality in Cordillera de Yanachaga, Pasco department, at elevations between 1000 and 1150 m, in the upper Amazon basin of central Peru (Fig. 7). This new species inhabits the premontane forest of the Rio Huancabamba canyon. The distribution lies within the Yanachaga Chemillen National Park and in the ecoregions of Selva Alta (400 - 1000 m) and Yungas (500 - 2300 m), according to Brack-Egg (1986) and Penaherrera del Aguila (1989). All individuals were collected at night, on leaves and branches of bushes up to 2 m above the ground, along ravines in Quebrada Honda and Quebrada Shuler, both drainages of the Rio Huancabamba. Sympatric amphibians were Bolitoglossa peruviana Boulenger, 1883, Leptodactylus rhodonotus Guenther, 1869, Pristimantis diadematus Jimenez de la Espada, 1875, P. minutulus Duellman & Hedges, 2007, Pristimantis sp., Rhinella aff. leptoscelis Boulenger, 1912, and R. poeppigii Tschudi, 1845. Recently metamorphosed juveniles of Osteocephalus vasquezi sp. nov. were on the rocks and leaves of low bushes on the shores of Quebrada Honda on the second half of August. The ravine of Quebrada Honda has a torrential stream of clear waters and a rocky bottom. Tadpoles of O. vasquezi sp. nov. were observed adhered to rocks, presumably with their oral disk, in the narrow and very torrential portion of Quebrada Honda and in the Huancabamba River. Tadpoles of Rhinella aff. leptoscelis were found in the same stream, but in lower abundance.
etymology
Etymology. The specific name is a patronym for Pedro Vasquez Ruesta, a Peruvian forest engineer, who is a pioneer in the wildlife management in Peru. Since 1978 he has worked for the development of wildlife management and protected natural areas as a professor at the Faculty of Forestry at Universidad Nacional Agraria La Molina, Lima, Peru, teaching to generations of forest engineers about wildlife management and conservation. During his academic life, Pedro Vasquez Ruesta made many contributions to the field of conservation of natural resources, advising theses and published scientific articles especially about the management of caimans and deer.