Pristimantis jester, Means, Bruce & Savage, Jay M., 2007

Means, Bruce & Savage, Jay M., 2007, Three New Malodorous Rainfrogs of the Genus Pristimantis (Anura: Brachycephalidae) from the Wokomung Massif in west-central Guyana, South America, Zootaxa 1658, pp. 39-55 : 45-48

Pristimantis jester n. sp.

( Figs. 3 , 4 , 5 )

Jester Rainfrog

Holotype. USNM 563631, an adult male collected from the round-topped summit on the Wokomung Massif called Mt. Wokomung, Potaro-Siparuni District, west-central Guyana; 05° 04’ 03.3” N, 59° 51’ 41.8” W, 1560 m; collected on 25 July 2003 by D. B. Means (field collection number DBM-3154, CPI-10327).

Paratopotype. USNM 563632, an adult male collected on 25 July 2003 by D. B. Means (field collection number DBM-3154; CPI 10328).

Other Paratypes. USNM 563633, an unsexed adult collected on the flat-topped summit on the Wokomung Massif called Little Ayanganna, Potaro-Siparuni District, Guyana; 05° 04’ 54.7” N, 59° 50’ 25.5” W, 1650 m; collected on 28 July 2003 by D. B. Means (field collection number DBM-3155, CPI 10330). ROM 43303, N slope of Mt. Wokomung, Potaro-Siparuni District, west-central Guyana; 05° 07' 46" N, 59° 49' 16" W, 1234 m; collected 27–31 October 2004 by R. MacCullough, A. Lathrop, and S. Khan. ROM 43306, N slope of Mt. Wokomung, Potaro-Siparuni District, west-central Guyana; 05° 05' 33" N, 059° 50' 35" W, 1411 m; collected 3–5 November 2004 by R. MacCulloch, A. Lathrop, and S. Khan.

Diagnosis. A small species (SL 19.4–22.8 mm) that differs from all other Guayana Shield species of the P. unistrigatus group in lacking both an auditory apparatus and toe webbing. Pristimantis avius ( Myers and Donnelly, 1997) , P. marahuaka ( Fuentes and Barrio-Amors, 2004) , P. memorans ( Myers and Donnelly, 1997) , P. pulvinatus ( Rivero, 1968) , P. saltissimus (see below), P. zimmermanae ( Heyer and Hardy, 1991) , and sp. 2 of Lescure and Marty (2000) also lack toe webbing but a tympanum and ostia pharyngea are present in these taxa ( Fig. 4 ).

Etymology. The name jester is to be treated as a noun in apposition. By implication the name refers to the brilliant red and green dorsal coloration of this species that is reminiscent of the garb of a medieval court jester .

General characteristics. Head relatively broad; HW/HL = 86–92%, snout subovoid in dorsal outline, rounded in profile. Canthus rostralis concave. Loreal region concave, upper lip not flared in cross-section; low glandular postrictal area. Choanae round, not concealed by maxillary arch, much larger than the small, oblique and widely separated vomerine tooth patches that lie posterior and internal to choanae. No vocal slits or sac; no ostia pharyngea. Upper surfaces smooth. EW/IOD = 108–130%. No tympanum, or annulus tympanicus or supra- or post-tympanic ridge. Finger II longer than Finger I when adpressed together; relative finger lengths III>IV>II>I. No nuptial pads. Disc cover on Finger I small, slightly widened. Disc covers on Fingers II to IV expanded, rounded, about equal in size and larger than disc cover on Finger II; width of cover on Finger III less than half width of eye; pads broadened on all fingers. No finger ridges, fringes or webbings. Subarticular tubercles under fingers and toes round, globular in profile; no supernumerary tubercles; thenar tubercle low, round, smaller than subarticular tubercles; palmar tubercle larger, bifid; 5–6 small, low accessory palmar tubercles. No well developed ulnar tubercles or fold. Heel smooth. Discs on most toes smaller than finger discs; disc on Toe IV larger than disc on Finger III; disc covers rounded, even; disc pads broadened. Relative toe lengths IV>V>III>II>I; Toe V longer than Toe III when adpressed against Toe IV reaching to base of distal subarticular tubercle on Toe IV; Toe III reaching slightly beyond the penultimate subarticular tubercle when adpressed to Toe IV. No toe ridges, fringes or webbings; supernumerary tubercles under toes; plantar surface with many small low tubercles; inner metatarsal tubercle elongate, much larger than small round outer; no tarsal fold or tubercle ( Fig. 5 ). No inguinal gland; venter coarsely areolate; throat and under surfaces of limbs smooth; pericloacal area granulate. Legs relatively short, heels slightly overlapping when legs folded at right angles to sagittal plane, C/SL = 52–61%. See Table 1 for summary statistics.

Color in life. Upper surfaces of head and body extremely variable with dark red, light green, and black marbling. In some specimens the red predominates but in others the green and black are more extensive. In one specimen (USNM 563632) a bold, wide, pure orange stripe runs from the tip of the snout to the cloaca; another specimen (USNM 563633) was mostly yellow-green dorsally with four bright red lateral blotches; head olive green, mottled green and black, or with a broad orange medial stripe. Upper lips with red and olive green patches set off by thin yellow green vertical lines; upper arm olive green; lower arm with one or two red and green equally wide crossbands; finger and toe discs dark red to dark gray; upper leg surface with 3 or 4 alternating red and olive green crossbands continuing onto the crus when legs are folded against the body; lower lip not visible in lateral view; throat, belly, and ventral surfaces of arms and legs mottled in cream and black except in the specimen with the bold middorsal stripe which had a cream colored, midventral longitudinal stripe; upper 2/5 of iris blue-gray against the sclera, changing to metallic brown around and below the iris. No color changes were noted between day and night.

Color in preservative. Upper surfaces of head and body dark brown with faint, lighter brown streaks and blotches. Upper arm uniformly dull white to tan; forearm with one or two broad dark brown bands alternating with dull cream; hand and fingers similar but the bands narrower and more numerous; finger and toe discs dark gray; upper and lower leg surfaces with three or four alternating dark and light bands, continuing onto the crus when the legs are folded against the body. Lower lip and throat dark brown with dull white marbling or specking, continuing onto the belly and undersurfaces of the legs; palmar surfaces similar to throat and belly, but plantar surfaces uniformly dark gray.

Measurements of holotype (in mm). SL 22.8; HL 9.5; HW 8.5; EW 3.0; IOD 2.3; E 4.2; TY 0; C 12.6; FL10.9.

Habitat and habits. Dense cloud forest approaching tepui scrub forest (Huber et al. 1995). The trees were no more than 10 m high with trunks, stems, and leaves densely covered with epiphytes ranging from mosses and a gooey, slimy alga to bromeliads and large aroids. Forest included trees of the genera Podocarpus, Weinmannia , and Clusia . Weather during time of collecting was raining, alternating with cloudy skies and blowing mists. USNM 563631 and 563632 were collected on the forested dome of the Wokomung Massif (Mt. Wokomung) within 3 m of each other at about 2 m off the ground from a tangle of dense vines and moss hanging from the low canopy. These two frogs were vocalizing contemporaneously (call unrecorded) with two or three other individuals that were not located. USNM 563633 was collected from a Clusia forest on the summit of Little Ayanganna. When grasped, these bright little frogs emitted a foul odor and tasted bitter. The odor persisted in the collector’s hand for five or 10 minutes following capture and could be smelled in the plastic bag in which they were confined.

Distribution. Known only from the tops of the two highest summits (Mt. Wokomung and Little Ayanganna) of the Wokomung Massif ( Fig. 3 ) of west-central Guyana (1411–1650 m).

Figures

FIGURE 3. Map of Guyana with the location of the Wokomung Massif in the Pakaraima Mountains (gray shading) and in relation to some other teuis in Guyana. Map modified from one supplied by Philippe J. R. Kok.

FIGURE 4. Pristimantis jester new species. a = USNM 563631, holotype; b = USNM 563632, paratopotype with middorsal orange stripe; c = ventral aspects of a and b, respectively; d = USNM 563633, paratype.

FIGURE 5. Pristimantis jester new species. Hand (left) and foot (right). USNM 563631 holotype. Black bars = 5.0 mm.