Dendrophryniscus davori, Cruz & Caramaschi & Fusinatto & Brasileiro, 2019

Cruz, Carlos Alberto Gonçalves, Caramaschi, Ulisses, Fusinatto, Luciana Ardenghi & Brasileiro, Cinthia Aguirre, 2019, Taxonomic review of Dendrophryniscus brevipollicatus Jiménez de la Espada, 1870, with revalidation of D. imitator (Miranda-Ribeiro, 1920) and D. lauroi Miranda-Ribeiro, 1926, and description of four new related species (Anura, Bufonidae), Zootaxa 4648 (1), pp. 27-62 : 42-45

Dendrophryniscus davori sp. nov.

( Figs. 9–10 )

Holotype. MNRJ 58300 , adult male, collected at Baixo Caledônia (22º21’S, 42º35’W, Datum WGS 84; 1600 m altitude), Municipality of Nova Friburgo , State of Rio de Janeiro, Brazil, by T.A. Dorigo, C.C. Siqueira and D. Vrcibradic, on 17 March 2009.

Paratypes. MNRJ 58301 , adult female, and MNRJ 58302 , adult male, collected with the holotype ; MNRJ 60700 , juvenile, collected at the type locality, by D. Vrcibradic, on 01 November 2009 .

Diagnosis. The species is characterized by: (1) medium size for the genus ( SVL 18.9–22.1 mm in males, 24.2 mm in female); (2) body slender, elongated; (3) snout mucronate in dorsal view; (4) canthus rostralis straight with a tubercle nearer to the eye than to the snout; (5) presence of a longitudinal set of white granules behind the corner of the mouth; (6) surfaces of upper eyelid with few granules sparse and external margin conspicuous; (7) tip of the third and fourth fingers poor expanded laterally; (8) skinfold poor developed on the articulation of the first and second phalanges of the fingers II, III, and IV; (9) male with a very developed nuptial pad with horny asperities conspicuous and pigmented on finger I (10) fingers slightly fringed and webbed only at base.

Comparisons with other species. Dendrophryniscus davori sp. nov. is distinguished from D. proboscideus by the smaller size ( SVL 18.9–22.1 mm in males; SVL 39.2–46.4 mm in males of D. proboscideus ); D. davori sp. nov. is distinguished from D. krausae and D. stawiarskyi by the slender body with uniform shape (robust and enlarged posteriorly in those species); D. davori sp. nov. is distinguished from D. berthalutzae , D. carvalhoi , D. krausae , D. lauroi , D. oreites , D. proboscideus , D. skuki , and D. stawiarskyi by the snout mucronate in dorsal view (snout rounded in D. berthalutzae , D. carvalhoi , D. lauroi , and D. stawiarskyi ; snout truncate in dorsal view in D. krausae , D. oreites , and D. proboscideus ; snout long, narrow, spatulate, with parallel lateral borders and rounded tip in D. skuki ); by the canthus rostralis straight D. davori sp. nov. is distinguished from D. berthalutzae , D. brevipollicatus , D. haddadi , D. imitator , D. izecksohni , D. jureia , D. oreites , D. organensis , D. proboscideus , and D. skuki (canthus rostralis slightly curved); by the canthus rostralis with a tubercle nearer to the eye than the nostril, D. davori sp. nov. differs from all congeneric species (canthus rostralis without tubercle); the presence of longitudinal set of pronounced granules posterior to the corner of mouth distinguishes D. davori sp. nov. from D. lauroi (elliptical set of shallow granules), D. brevipollicatus , D. izecksohni ., and D. jureia (elliptical set of pronounced granules), D. imitator (two pronounced granules), and absent in D. carvalhoi , D. haddadi , D. organensis , D. proboscideus , D. skuki , and D. stawiarskyi ; D. davori sp. nov. presents the surfaces of upper eyelid with few granules sparse and external margin conspicuous (surfaces of upper eyelid with numerous granules and with a conspicuous margin in D. brevipollicatus and D. izecksohni ); D. davori sp. nov. is distinguished from D. brevipollicatus , D. lauroi , and D. organensis by the tip of the third and fourth fingers poorly or not expanded laterally (laterally expanded in those species); D. davori sp. nov. is distinguished from D. brevipollicatus by the presence of a skinfold poorly developed on the articulation of the first and second phalanges of the fingers II, III, and IV (well developed in this species); D. davori sp. nov. is distinguished from D. brevipollicatus , D. imitator , D. jureia , D. lauroi , and D. leucomystax by the presence of very developed nuptial pad in male (absent in D. leucomystax , poor developed in D. jureia , and moderate in D. brevipollicatus , D. haddadi , D. imitator , and D. lauroi ); D. davori sp. nov. is distinguished from D. berthalutzae , D. carvalhoi , D. haddadi , D. izecksohni , D. krausae , D. lauroi , D. oreites , D. skuki , and D. stawiarskyi by the fingers slightly fringed and webbed only at base (fingers fringed and webbed about one third in D. izecksohni and D. jureia ; fingers not fringed and webbed only at base in D. krausae ; not fringed nor webbed in D. berthalutzae , D. carvalhoi , D. haddadi , D. imitator , D. lauroi , D. oreites , D. skuki , and D. stawiarskyi ).

Description of holotype. Body slender, elongated ( Fig. 9 ); head triangular, longer than large, head length 34.8% of SVL; snout mucronate in dorsal view, acute in lateral view ( Fig. 10 ); snout 51.9% of head length; presence of a small tubercle under the tip of snout in ventral view; nostrils not protuberant, small and elliptical, located laterally near the tip of snout, below the canthus rostralis; internarial distance 47.5% of eye to snout distance; eye diameter 50% of eye to snout distance and 71% of interorbital distance; eye protuberant; canthus rostralis almost straight with a tubercle nearer to the eye than the nostril; loreal region vertical; choanae small, circular, and very far from witch one; tongue long and few enlarged posteriorly; vocal sac indistinct; vocal slits present. Arms strongly robust; hand with fingers robust, slightly fringed and webbed only at base, distal end of fingers globose, tip of the third and fourth finger slightly expanded laterally; male with a very developed nuptial pad with conspicuous and pigmented horny asperities on finger I; relative lengths of fingers I< II < IV < III; subarticular tubercles single, rounded; outer metacarpal tubercle large, oval; inner metacarpal tubercle elliptical, almost the same size of outer metacarpal tubercle; supernumerary tubercles few, small, and disperse; skinfold few developed on the articulation of the first and second phalanges of the fingers II, III, and IV. Thigh length slightly shorter than tibia length; sum of thigh and tibia lengths about 81% of snout–vent length. Tarsal length about 25% of the snout vent length. Foot with toes robust, not fringed; interdigital webbing moderately developed, webbing formulae: I1–2II1–3III2–4 IV3– 21 /2V; distal end of toes globose, not expanded laterally, relative lengths of toes I< II < III <V< IV; subarticular tubercles single, rounded, bigger than those of the fingers; outer metatarsal tubercle small, elliptical; inner metatarsal tubercle oval and large, approximately twice the outer; supernumerary tubercles numerous. Dorsal and lateral surfaces covered by spinulose granules, irregularly distributed, with different sizes; ventral surfaces densely covered by prominent white granules, regularly distributed; surfaces of upper eyelid with few granules sparse and external margin conspicuous; presence of a longitudinal set of white granules behind the corner of the mouth.

Color in preservative. Dorsum grayish light to dark brown, delimited by a whitish margin; a head blotch ex- tending on the upper eyelids merging with an ‘X’ shaped blotch on the scapular region and an inverse ‘Y’ shaped blotch on the sacral region (fade on the holotype) extending to the inguinal region; one transversal bar on forearm and one blotch on elbow; one transversal bar on thigh, tibia, and tarsus, and one small blotch on heel; a lateral stripe starting at the snout, passing on the eye and reaching the inguinal region; all bars, blotches, and stripes are dark brown; a marked white blotch under the eye and white tubercles at the corner of the mouth; ventral surface uniformly whitish.

Measurements of holotype. SVL 22.1; HL 7.7; HW 6.7; IND 1.9; ESD 4.0; ED 2.0; IOD 2.8; THL 8.8; TL 9.2; TAL 5.6; FL 9.2.

Variation. Specimens are congruent with respect to the morphological characters. Measurements of male and female are presented in Tables 2 and 3; juvenile paratype measured 15.7 mm SVL. Sexual dimorphism can be observed on SVL (larger in female), on arms (slightly more robust in male), finger I (robust in male), and nuptial pad (on finger I of male). On the holotype the dorsal blotches are less evident.

Distribution. Dendrophryniscus davori is known only from the type locality ( Fig. 17 ), Baixo Caledônia, Municipality of Nova Friburgo, State of Rio de Janeiro, Brazil.

Natural history. This species is associated to forested areas, at 1600 m above sea level.

Etymology. The name of the species honors our friend Dr. Davor Vrcibradic, from Universidade Federal do Estado do Rio de Janeiro ( UNIRIO), by his contribution to the knowledge of Brazilian amphibians and reptiles.

Figures

FIGURE 9. Dendrophryniscus davori sp. nov., holotype, MNRJ 58300 (SVL 22.1 mm). Dorsal and ventral views.

FIGURE 10. Dendrophryniscus davori sp. nov., holotype, MNRJ 58300 (SVL 22.1 mm). Dorsal and lateral views of head, ventral views of hand and foot.

FIGURE 17. Map of geographic distribution of species of Dendrophryniscus brevipollicatus group reviewed in this study. RJ, State of Rio de Janeiro; SP, State of São Paulo.