Hyloscirtus diabolus, Rivera-Correa, Mauricio, García-Burneo, Karla & Grant, Taran, 2016

Rivera-Correa, Mauricio, García-Burneo, Karla & Grant, Taran, 2016, A new red-eyed of stream treefrog of Hyloscirtus (Anura: Hylidae) from Peru, with comments on the taxonomy of the genus, Zootaxa 4061 (1), pp. 29-41 : 30-35

Hyloscirtus diabolus sp. nov.

( Figs. 1–3 )

Holotype. CORBIDI 12885, adult male, Peru, Departamento de Amazonas, Provincia de Chachapoyas, Distrito La Jalca, km 10 from La Colpa–Rodríguez de Mendoza (-6.398944, -77.226278, 2300 m a.s.l.) Collected 14 November 2012 by Karla García-Burneo.

Paratype. MUSA 3864, adult male, Peru, Departamento de Amazonas, Provincia de Pedro Ruiz Gallo, Comunidad Shipasbama (-5.845833, -78.071944, 2180 m a.s.l.). Collected on 18 September 2011 by Roy Santa Cruz Farfán.

Diagnosis. Hyloscirtus diabolus ( Fig. 1 ) can be diagnosed by the following characters: large size (SVL 82.3– 89.2 mm, n = 2); vertical keel in the snout and upper lip cleft in the region of the premaxilla; vomerine odontophores with a conical-shape and a gap medially, each process with two or three prominent teeth; large, thick, supracloacal flap and supratympanic fold present; finger webbing formula: I 2 ½ –2½ II 1 2/3–2 2/3 III 2 +– 2 IV, toe webbing formula: I 1 1/2 –2- II 1 -–2 III 1 1/2 –2 1/2 IV 2 1/2– 1- V; nuptial pad absent; hypertrophied forelimbs and enlarged, curved and protruding spine prepollex present; fleshy calcar tubercle present; dorsum, thighs, shanks, finger, toes and discs brown with abundant tiny yellow marks; iris dark red without reticulation.

Comparison. The only species of the H. larinopygion species group with hypertrophied forelimbs in adult males and broad elliptical prepollex, modified as a projecting spine, are H. tapichalaca (Kizirian et al. 2003) , H. condor Almendáriz et al. 2014 , and H. diabolus . The remaining species of the group lack the hypertrophied forelimbs and their prepollex is trapezoidal (Kizirian et al. 2003; Rivera-Correa and Faivovich 2013; Table 1 ). Hyloscirtus diabolus differs from H. condor by having a strongly well developed, fleshy, heel tubercle (absent in H. condor ), dark red iris (iris golden with fine tan reticulations in H. condor ), gular region and belly dark reddish gray with pink marks in preservation (belly olive without marks and chest is light gray in H. condor ), vertical keel in the snout and upper lip cleft in the region of the premaxilla (absent in H. condor ) and greater adult male SVL ( H. condor : 64.8–73.8 mm, n = 7 in). The new species differs from H. tapichalaca in dorsal and lateral color pattern: dorsum gray or brown, flanks gray brown, bearing pink-orange marks more conspicuous in axillary and inguinal regions, lateral and lower margin of cloaca, knee, elbow, and outer margin of forearm white in H. tapichalaca ; and ventral color pattern: gular region and belly dark reddish gray with pink marks in preservation to H. diabolus (belly gray-blue and chest is light gray in H. tapichalaca ), digital discs brown (digital discs white in H. tapichalaca ), iris dark red (iris yellow-gold with fine black reticulations in H. tapichalaca ), upper lip cleft in the region of the premaxilla (absent in H. tapichalaca ) and greater adult male SVL ( H. tapichalaca : 59.1–63.8 mm, n = 8). For a summary of others diagnostic characters of the H. larinopygion species group, see Table 1 .

……continued on the next page Description of holotype. Adult male, 82.3 mm SVL ( Fig. 2 ). Body robust. Head 13% wider than long; head as wide as body; head width 35% of SVL; head length 27% of SVL. Snout rounded in dorsal view, truncate in profile ( Fig. 3 A–B); canthus rostralis rounded, distinct; loreal region weakly concave, nearly vertical; lips rounded, faintly flared; nostrils slightly protuberant, directed anterolaterally, located at level of anterior margin of lower jaw. Vertical keel on snout and upper lip cleft in region of premaxilla. Dorsal surface of internarial region concave. Interorbital distance slightly greater than upper eyelid width. Eye prominent, diameter greater than eye–nostril distance. Tympanum barely visible, round, positioned vertically such that is not visible from above; diameter 51% of eye diameter; tympanic annulus inconspicuous. Supratympanic fold prominent, extending from posterior to eye to posterior margin of arm insertion, slightly covering dorsal edge of tympanic membrane. Region between head and suprascapula depressed. Vomerine odontophores conical, separated by gap medially, positioned posterior to choanae; each process with 2–3 prominent teeth. Choanae small, ovoid, separated by a minimum distance greater than 3.5 times their maximum diameter. Tongue cordiform, barely free around lateral and posterior margin. Vocal slits longitudinal, originating on lateral to tongue and extending extending to the corner of the mouth. Vocal sac evident externally, large, single, median, subgular. Mental gland absent.

Upper arms and forearms hypertrophied; axillary membrane absent; ulnar fold and tubercles absent. Fingers short, thick, bearing large, ovoid discs, circumferential groove of each disc clearly defined; width of disc on Finger III 46 % greater than tympanum diameter. Relative lengths of fingers I <II <IV <III.; webbing formula: I – II 1 2/3– 2 2/3 III 2 +– 2 IV ( Fig. 3 C). Distal and proximal subarticular tubercles large, single, rounded, conical; distal tubercles on Finger IV globular. Palmar surfaces with deep folds. Large supernumerary tubercles, high and round, distributed over base of fingers. Outer metacarpal tubercle diffuse. Inner metacarpal tubercle large, its shape contouring underlying distal prepollex that is modified into an enlarged, protruding spine. Nuptial pad absent. Hind limbs robust; tibia length 50% of SVL; foot length 47% of SVL. Calcar tubercle large, fleshy; tarsal fold or tubercles absent; metatarsal fold thick. Inner metatarsal tubercle large, ovoid; outer metatarsal tubercle small, round. Toes short, lateral fringes absent, discs smaller than those of fingers, slightly wider than digit. Relative length of toes: I <II <V <III <IV; toe webbing formula: I 1 1/2 –2- II 1 -–2 III 1 1/2 –2 1/2 IV 2 1/2– 1- V ( Fig. 3 D). Subarticular tubercles large, round, conical; single row of smaller supernumerary tubercles along axis of each toe. Cloacal opening directed posteriorly at upper level of thighs; supracloacal flap large, thick; margins of vent with numerous small folds; cloacal sheath short. Dorsal skin, gular region, pectoral region and flanks smooth; belly and proximal ventral region of thighs granular.

Color of holotype in life. Dorsum, flanks, anterior and posterior surfaces of thighs and shanks, calcar tubercle, dorsal surfaces of fingers and toes brown with an abundant tiny yellow marks; discs dark bluish gray ventrally. Gular region and ventral surfaces dirty gray with an abundant small yellow flecks and spots; ventral surfaces of hands, feet, and webbing dirty gray. Pericloacal region light gray. Iris solid dark red, without reticulations.

Color of holotype in preservative. Dorsum, flanks, anterior and posterior surfaces of thighs and shanks, dorsal surfaces of fingers and toes dark gray with an abundant light gray marks. Gular region and belly, ventral surfaces of thighs and shanks dark reddish gray with pink flecks and spots; hands, feet, webbing, and pericloacal region dirty gray.

Measurements of holotype (in mm). SVL 82.3; HL 22.4; HW 28.5; ED 9.0; END 5.7; NSD 3.7; IND 5.8; AMD 12.1; TD 2.7; FAL 14.3; FAB 12.0; HAL 29.7; THL 39.8; TL 41.0; TAL 22.0; FL 38.7; TFD 5.0; FTD 3.8.

Variation. The paratype MUSA 3864 (SVL = 89.2 mm) is remarkably larger than the holotype, possesses fewer yellow flecks and spots on the dorsum but more conspicuous on the loreal region, digits, flanks, thighs ( Fig. 4 ), and belly in life. Foot webbing is more extensive: I 2–2 2/3 II 1 2/3–2 2/ 3 III 2– 2 IV and I 1 - –1 1/ 2 II 1–2 III 1 1/3 –2- IV 2 -– 1- V. Other measurements of the paratype are: HL 23.9; HW 28.7; ED 8.8; END 6.0; NSD 3.9; IND 5.8; AMD 12.8; TD 2.7; FAL 14.3; FAB 11.8; HAL 30.5; THL 40.7; TL 44.0; TAL 25.6; FL 42.4; TFD 5.9; FTD 4.8.

Distribution and natural history. Hyloscirtus diabolus is currently known only from two localities approximately 100 km straight-line distance apart in the highlands on the eastern flank of the Cordillera Central, northern Peruvian Andes ( Fig. 5 ). The two known individuals were found in dense cloud forest adjacent to very rocky streams with strong flow and 30–35º slope. The specimens were collected while calling at night, perched on tree branches ca. 1.80 m above the ground and ca. 2 m from the edge of the stream. When handled, they clung tightly to the substrate, acquired a position with the head directed toward the belly and limbs pressed to the abdomen, and secreted a white, viscous, sticky, liquid over the entire body. Advertisement calls, reproductive biology, and tadpoles are unknown. No other anuran species was found syntopically with H. diabolus

Etymology. The specific epithet diabolus is Latin for devil and is used as a noun in apposition. The devil according to Christianity is the spirit of evil and enemy of God, often represented as the ruler of hell and depicted as a human figure with horns, cloven hoofs, fire-red eyes, trident, and tail. The species name is in allusion to the hypertrophied forelimbs, enlarged prepollex with a projecting spine, trident vomers, and dark red iris in life.

Figures

FIGURE 1. Hyloscirtus diabolus sp. nov. in life (CORBIDI 12885, holotype, adult male, 82.3 mm SVL). Photos: K. García- Burneo.

FIGURE 2. Dorsal and ventral views (in preservative) of the holotype of Hyloscirtus diabolus sp. nov. (CORBIDI 12885; adult male, 82.3 mm SVL).

FIGURE 3. Hyloscirtus diabolus sp. nov. (CORBIDI 12885, holotype). (A) Head in lateral view (B) head in dorsal view; (C) left hand in ventral view; (D) left foot in ventral view. Scale bar = 10 mm.

FIGURE 4. Hyloscirtus diabolus sp. nov. in life (MUSA 3864, paratype, adult male, 89.2 mm SVL). Note the dark marks (scars) in the anterior region of dorsum, which are consistent with the occurrence of male combat (see text). Photo: R. Santa Cruz.

FIGURE 5. Geographic distribution of Hyloscirtus diabolus sp. nov. (holotype locality, star; paratype locality, dot), H. condor (triangle), and H. tapichalaca (square).

Tables

TABLE 1. Cοmparisοn οf sοme diagnοstic characters in species οf the Hyloscirtus larinopygion grοup. Sοurces ∶ (1) Almendariz et al. 2014; (2) Ardila-Rοbayο et al. (1993); (3) Cοlοma et al. (2012); (4) Duellman (1973); (5) Duellman and Altig (1978); (6) Duellman and Berger (1982); (7) Duellman and Hillis (1990); (8) Duellman and Cοlοma (1993); (9) Kizirian et al. (2003); (10) Mueses-Cisnerοs and Anganοy-Criοllο (2008); (11) Mueses-Cisnerοs and Perdοmο-Castillο (2011); (12) Ruiz-Carranza and Lynch (1982); (*) this study.

Species H. antioquia	Dοrsal pattern Reddish brοwn; with οr withοut scattered οrange blοtches	Fοrelimbs Nο hypertrοphied	Iris cοlοr Gray with burgundy reticulatiοns	vοmerine teeth In cοntact οr nοt, 12‾ 20 teeth⁄each	Nuptial pad Medial and distal cοmpοnent; dark brοwn epidermal prοϳectiοns	Prepοllex Τrapezοidal	Calcar Sοurce tubercle Present * (2)
H. caucanus	Brοwn οr reddish brοwn with dark brοwn scattered blοtches; with οr withοut middοrsal stripe	Nο hypertrοphied	Pale yellοw with brοwn reticulatiοns	In cοntact, 10‾14 teeth⁄each	Distal cοmpοnent οnly; creamy white	Τrapezοidal	Present οr * Absent (2)
H. condor H. criptico H. diabolus	Light brοwn with abundant yellοw marks Grayish brοwn, densely stippled with minute cream flecks and bright οrange blοtches Brοwn with abundant yellοw marks	Hypertrοphied Nο hypertrοphied Hypertrοphied	Gοlden with minute reticulatiοns Dark gray Dark red, withοut reticulatiοns	Nο cοntact, 3‾4 teeth⁄each In cοntact οr nοt, 8‾15 teeth⁄each Nο cοntact, 2‾3 teeth⁄each	Absent Absent Absent	Spine Τrapezοidal Spine	Absent (1) Present * (3) Present *
H. larinopygion H. lindae	Light brοwn tο dark brοwn; with οr withοut dark brοwn reticulatiοn Dark metallic brοwn	Nο hypertrοphied Nο hypertrοphied	Gοlden οr silver with black reticulatiοns Dull bluish gray with minute black flecks	In cοntact οr nοt, 8‾15 teeth⁄each In cοntact, 11‾13 teeth⁄each	Medial and distal cοmpοnent; creamy white Distal cοmpοnent; creamy white	Τrapezοidal Τrapezοidal	Present οr * Absent (4) Present οr * Absent (3, 5)
H. pacha	Dark brοwn with metallic οrange flecks	Nο hypertrοphied	Οlive brοwn	In cοntact, 11‾15 teeth⁄each	Absent	Τrapezοidal	Present * (3, 7)
H. pantostictus	Οlive-brοwn with small οrange spοts	Nο hypertrοphied	Dark gray	In cοntact οr nοt, 10‾14 teeth⁄each	Medial and distal cοmpοnent, light brοwn epidermal prοϳectiοns	Τrapezοidal	Present οr * Absent (3, 5)