Phrynopus tribulosus, Duellman, William E. & Hedges, Blair, 2008

Duellman, William E. & Hedges, Blair, 2008, Two new minute species of Phrynopus (Lissamphibia: Anura) from the Cordillera oriental in Peru, Zootaxa 1675, pp. 59-66 : 63-64

Phrynopus tribulosus new species

Holotype: KU 291630, adult male, from 2.9 km N, 5.5 km E (airline) Oxapampa, 2600 m, 10°32'38"S, 75°21'10"W, Departamento Pasco, Peru, obtained on 3 July 1987 by S. Blair Hedges.

Diagnosis. A species of Phrynopus characterized by: (1) skin on dorsum finely shagreen with scattered small tubercles; that on venter smooth; dorsolateral folds absent; discoidal fold absent; (2) tympanic membrane not differentiated; tympanic annulus absent; (3) snout moderately short, bluntly rounded in dorsal view, rounded and inclined anteroventrally in profile; (4) upper eyelid bearing small tubercles, narrower than IOD; cranial crests absent; (5) dentigerous processes of vomers absent; (6) vocal slits and nuptial pads absent; (7) Finger I shorter than Finger II; tips of fingers rounded, barely expanded; (8) fingers lacking lateral fringes; (9) ulnar tubercles absent; (10) heel bearing one subconical tubercle, outer edge of tarsus with row of subconical tubercles; inner tarsal fold absent; (11) inner metatarsal tubercle ovoid, about equal in size to rounded outer metatarsal tubercle; supernumerary plantar tubercles absent; (12) toes lacking lateral fringes; webbing absent; Toes III and V equal in length; tips of toes rounded; (13) dorsum green with brown markings; (24) SVL in one male 15.2 mm.

The presence of a single subconical tubercle on the heel and a row of subconical tubercles on the outer edge of the tarsus distinguishes Phrynopus tribulosus from most other species in the genus. Phrynopus barthlenae Lehr & Aguilar, P. k o t o s h Lehr, and P. oblivius Lehr have several small tubercles on the heel, and the last two species also have small tubercles on the outer edge of the tarsus; of these species, P. barthlenae and P. oblivius differ from P. tribulosus in having Toe V slightly longer than Toe III (instead of equal in length) and in color pattern—gray and black dorsally and ventrally in P. barthlenae , mottled tan and brown dorsally and ventrally in P. k o t o s h, and white spots on a brown dorsum and red venter in P. oblivius . The tubercles in P. bracki and P. dagmarae are larger and much like those in P. tribulosus ; P. bracki differs from P. tribulosus in having Toe V slightly longer than Toe III (instead of equal in length), vomerine teeth present (absent in P. tribulosus ) and in coloration—predominately brown dorsally and ventrally. Phrynopus tribulosus is most like P. dagmarae , which differs by being larger with a more robust body and in lacking vocal slits. Also, P. dagmarae has a red blotch in the groin; some individuals are brown and others are green ( Fig. 1 D). See Table 1 for comparisons with all other species of Phrynopus .

Description of holotype. Adult male with white testes; body moderately slender; head as wide as body, slightly longer than wide; head width 33.6% SVL; head length 34.9% SVL; snout bluntly rounded, nearly truncate in dorsal view, rounded and slightly inclined anteroventrally in profile; canthus slightly curved, rounded in profile; loreal region distinctly concave; lips not flared; nostrils not protuberant, directed laterally; internarial region not depressed; top of head slightly convex; width of upper eyelid much less (64.7%) than IOD; eye large, its diameter much greater than its distance from nostril; tympanum and supratympanic fold absent. Tongue longer than broad, shallowly notched posteriorly, free behind for about one fourth of its length; choanae small, ovoid, partially concealed by palatal shelf of maxillary; dentigerous processes of vomers not visible; vocal slits absent.

Forelimb slender; ulnar tubercles absent; palmar tubercle large, ovoid, slightly bifurcate distally, barely larger than elliptical thenar tubercle; subarticular tubercles large, rounded to subconical; supernumerary tubercles absent; fingers slender, lacking lateral fringes; relative lengths of fingers I<II<IV<III; tips of fingers barely expanded, rounded, lacking circumferential grooves; nuptial pads absent. Hind limb short, moderately slender; tibia length 44.1% SVL; foot length 44.7% SVL; heel bearing small, subconical tubercle; outer edge of tarsus having three broad subconical tubercles; inner tarsal fold absent; inner metatarsal tubercle ovoid, about same size as round outer metatarsal tubercle; subarticular tubercles small, rounded; supernumerary tubercles absent; toes slender, lacking lateral fringes; relative lengths of toes I<II<III=V<IV; tips of toes narrow, rounded, lacking circumferential grooves.

Skin on dorsum smooth with scattered, small, round tubercles most prominent on flanks and hind limbs; tubercles on upper eyelids small; dorsolateral folds absent; skin on venter smooth; discoidal fold not evident; skin around cloaca and ventrolateral to cloaca granular.

Coloration of holotype in preservative: Dorsum pale tan with brown markings consisting of canthal stripe, labial bars, postorbital stripe, interorbital bar, blotch on medial surface of forearm, and middorsal rectangular mark on body; cloacal area dark brown continuous with dark brown longitudinal stripe on posterior surface of thigh; flanks pale brown; faint brown bars on hind limbs; venter cream with brown blotches.

Coloration of holotype in life: Dorsal surfaces of head, body, and limbs dull green with dark brown markings consisting of canthal stripe, three labial bars on each upper lip, short postorbital stripe, broad interorbital bar, irregularly bordered diagonal mark from behind orbit to X-shaped mark on midbody, blotch on medial surfaces of forearms, and diagonal bars on hind limbs ( Fig. 1 B); flanks tannish green with brown smudge anteriorly and dark brown blotch in upper groin; posterior surfaces of thighs dark brown; Fingers I and II and Toes I–III dull greenish yellow; other digits brown; venter; posterior surfaces of thighs lacking flash marks; iris dark brown with gold flecks.

Measurements of holotype in mm: SVL 15.2; tibia length 6.7; foot length 6.8; head length 5.3; head width 5.1; interorbital distance 1.7; width of eyelid 1.1; internarial distance 1.7; eye-nostril distance 1.3; diameter of eye 2.0.

Distribution and ecology. The species is known only from the type locality in humid montane forest, where it was found deep within a mossy bank by day.

Etymology. The specific name is Latin meaning thorny. The name refers to the short, thorn-like tubercles on the heel and outer edge of the tarsus.

Discussion. Species of Phrynopus have restricted distributions at elevations of 2200–4400 m in the Andes in central Peru. Most frequently they are the only anurans found at the higher elevations, and there are few cases of sympatric pairs of species— P. dagmarae and P. tautzorum , P. heimorum and P. hortspauli , and P. kotosh and P. m o n t i u m all at elevations above 2900 m in Departamento Huánuco; P. juninensis and P. m o n t i u m as well as P. oblivius and P. peruanus at elevations in excess of 3000 m in Departamento Junín; P. juninensis and P. paucari at an elevation of 3600 m in Departamento Pasco ( Lehr 2007b; Lehr et al. 2002, 2005b). The type locality of the two new species at an elevation of 2600 m harbors three species of Phrynopus , the two species described herein plus P. bracki ( Hedges, 1990) .

In the Andes in central Peru species of Phrynopus generally occur at higher elevations than do Pristimantis . The localities in the vicinity of Oxapampa are the lowest for species of Phrynopus . At the type locality at 2600 m, the three species of Phrynopus occur sympatrically with Pristimantis bromeliaceus and P. rhabdocnemus , and at San Alberto at 2200 m, Phrynopus bracki occurs sympatrically with these same two species of Pristimantis , plus Pristimantis sagittulus ( Duellman and Hedges 2005; Lehr et al. 2004).

Figures

FIGURE 1. Species of Phrynopus: (A) P. auriculatus, KU 261633, male holotype, 13.4 mm SVL; (B) P. tribulosus, KU 261630, male holotype, 15.2 mm SVL.; (C) P. peruanus, MTD 46802, male, 22.5 mm SVL, from Puna of Maraynioc, Pasco, Peru; (D) P. dagmarae, MHNSM 20453, male, 26.6 mm SVL, from 15 km SE Maraypata, Huánuco, Peru. A and B by S. B. Hedges; C and D by E. Lehr.