Pristimantis saltissimus, 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 : 48-53

Pristimantis saltissimus n. sp.

( Figs. 3 , 6 , 7 )

Rocket Rainfrog

Holotype. USNM 563639, an adult female from the Wokomung Massif, near Falls Camp, Potaro-Siparuni District, west-central Guyana; 05° 05’ 25” N, 59° 50’ 18” W, 1385 m; collected on 19–23 July 2003 by D. B. Means (field collection DBM-3152; CPI 10335).

Paratopotypes. USNM 563634, an adult from the Wokomung Massif, summit of Mt. Wokomung, Potaro-Siparuni District, west-central Guyana; 05° 04’ 03” N, 59° 51’ 42” W, 1560 m; collected on 25 July 2003 by D. B. Means (field collection DBM-3154; CPI 10329). USNM 563635-563637, 563640, 563641, 563644, 563645, all from the Wokomung Massif, near Falls Camp, Potaro-Siparuni District, west-central Guyana; 05° 05’ 25” N, 59° 50’ 18” W, 1385 m; collected on 19 July 2003 by D. B. Means (field collection DBM-3152; CPI 10331-10333, 10336, 10337, 10340, 10341).

Other paratypes. ROM 43302, from north 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 A. Lathrop, S. Khan, and R. MacCulloch. ROM 43309 & 43310, from the base of the Wokomung Massif, Potaro-Siparuni District, west-central Guyana; 05° 06’ 35” N, 59° 48’ 37” W, 698 m; collected 23–26 October 2004 by A. Lathrop, S. Khan, and R. MacCulloch. ROM 43307, 43313, and 43314, from N slope of Mt. Wokomung, Potaro-Siparuni District, west-central Guyana; 05° 05’ 33” N, 59° 50’ 35” W, 1411 m, collected 3-5 November 2004 by A. Lathrop, S. Khan, and R. MacCulloch.

Referred material. USNM 563638, 563642-563643, 563646-563651, from near Falls Camp on the Wokomung Massif, Potaro-Siparuni District, west-central Guyana; 05° 05’ 25” N, 59° 50’ 18” W, 1385 m; collected 19–23 July 2003 by D. B. Means (field collection DBM-3152; CPI 10334, 10338, 10339, 10342- 10347). USNM 564165 & 564166, vicinity of a small, first-order creek on a terrace of the southern slope of Mt. Kopinang, SW part of the Wokomung Massif, Potaro-Siparuni District, west-central Guyana, 04° 04’ 50” N, 59° 52’ 43” W, ca. 1385 m; collected 6 December 2006 by D. B. Means and M. Kalamandeen (field collection DBM-3371; CPI 10357 & 10358). USNM 564167-564169, cloud forest summit of Mt. Kopinang, SW part of the Wokomung Massif, along a trail paralleling Kamana Creek for about 100 m west of the top of its cascade off of the summit at the E end of the trail, Potaro-Siparuni District, west-central Guyana, 05° 00’ 08” N, 59° 52’ 47” W, ca. 1538 m; collected 7 December 2006 by D. B. Means (field collection DBM-3372; CPI 10362, 10363, 10366). USNM 564170 & 564171, cloud forested summit of Mt. Kopinang, SW part of the Wokomung Massif, along a trail paralleling Kamana Creek for about 300 m west of the top of its cascade off of the summit at the E end of the trail, Potaro-Siparuni District, west-central Guyana, 05° 00’ 08” N, 59° 52’ 47” W, ca. 1570 m; collected 8 December 2006 by D. B. Means (field collection DBM-3373; CPI 10377 & 10378). USNM 564172 & 564173, on leaves 0.3-1.3 m off the ground in cloud forested summit of Mt. Kopinang, SW part of the Wokomung Massif, along a trail paralleling Kamana Creek for about 300 m west of its cascade off the top of the summit at the E end of the trail, Potaro-Siparuni District, west-central Guyana, 05° 00’ 08” N, 59° 52’ 47” W, ca. 1570 m; collected 10 December 2006 by D. B. Means, M. Kalamandeen (field collection DBM-3376; CPI 10384 & 10390). USNM 564174-564176, cloud forest summit of Mt. Kopinang, SW part of the Wokomung Massif, in the vicinity of the top of Kamana Creek Falls, Potaro-Siparuni District, west-central Guyana, 05° 00’ 08” N, 59° 52’ 47” W, ca. 1538 m; collected 10 December 2006 by D. B. Means (field collection DBM-3377; CPI 10395, 10397, 103403). USNM 564177-564179, all found at night on leaves 0.6-2.0 m off the ground in transitional forest (rainforest to cloud forest) next to a 300-m long trail on a terrace of the southern slope of Mt. Kopinang, SW part of the Wokomung Massif, Potaro-Siparuni District, west-central Guyana, 04° 04’ 50” N, 59° 52’ 43” W, ca. 1385 m; collected 11 December 2006 by D. B. Means and M. Kalamandeen (field collection DBM-3378; CPI 10414, 10416 & 10417).

Diagnosis. A small species (SL 16.0– 27.1 mm), one of eight Guiana Shield species in the P. unistrigatus group having the auditory apparatus present but lacking toe webbing ( Fig. 6 ). The principal features that distinguish P. saltissimus from these taxa are the character state of the tympanum and coloration in life as detailed below (features of P. saltissimus in parentheses). Pristimantis avius ( Myers and Donnelly, 1997) , 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) have prominent, large tympana and a distinct oticus tympanicus (indistinct tympanum and oticus tympanicus visible through the skin). P. marahuaka (Fuentes and Barrio-Amorós 2000) of Cerro Marahuaka , Venezuela, has a small, indistinct tympanum with the oticus tympanicus visible through the skin but is uniform brown above with abundant miniscule white spots, especially on the flanks and upper surfaces of the forearms and thighs, and the venter is pale yellow or dirty white in preservative, without dark markings (dorsum with dark markings and venter usually heavily marked with dark pigment).

Etymology. The name is from the Latin salto (to jump) + the superlative issimus in reference to the extreme jumping ability of this diminutive frog. In the field it was called the rocket frog.

General characteristics. Head longer than broad; snout subelliptical in dorsal outline; snout profile acuminate. Canthus rostralis concave. Loreal region concave, upper lip not flared in cross-section; weak cloacal tubercle present. Choanae round, not concealed by maxillary arch, small, about the same size as tiny oblique patches of vomerine teeth lying posterior to and between choanae. No vocal slits or sac. Surface of head shagreened, dorsum and upper limb surfaces shagreened with widely scattered dorsal pustules and/or a few short ridges. Upper eyelid with several large pustules. EW/IOD = 73–150%. Tympanum small, indistinct; annulus tympanicus visible under skin, width less than horizontal diameter of eye; TY/E = 21–37%; tiny ostia pharyngea present; no distinct supra- or post-tympanic fold. Finger II much longer than Finger I when adpressed together; relative finger lengths III>IV>II>I. No nuptial pads. Disc pad on Finger I only slightly wider than finger. Disc covers on Fingers II to IV expanded, even. Disc pads on Fingers III–IV about equal in size to that on Toe IV; width of disc on Finger III equals width of tympanum; disc pads on all fingers broadened. No fringes, ridges or webbings on fingers. Subarticular tubercles under fingers and toes low, round, and globular in profile; no supernumerary tubercles; thenar tubercle low, elongate, smaller than bifid palmar tubercle; several accessory palmar tubercles. No distinct ulnar tubercles or fold. Heel smooth or with very weak tubercles. Toe disc pads moderate, disc on Toe IV slightly smaller to about same size as on Finger III; disc cover expanded, even; disc pads broadened. Relative toe lengths IV>V>III>II=I; Toe V much longer than Toe III when adpressed against Toe IV, reaching distal subarticular tubercle; Toe III extends to the penultimate subarticular tubercle when adpressed against Toe IV. No fringes, ridges or webs on toes. No supernumerary tubercles under toes; plantar surface with numerous, small low tubercles; inner metatarsal tubercle elongate, outer metatarsal tubercle tiny, round; no tarsal fold or tubercle ( Fig. 7 ). No inguinal gland; venter coarsely areolate; throat and under surfaces of limbs smooth; pericloacal area granular. Legs relatively short, heels barely overlapping when legs folded at right angles to sagittal plane; C/SL = 53–64%. See Table 1 for summary statistics.

Color in life. Dorsal color pattern extremely variable due to pattern polymorphism as well as metachrosis ( Fig. 6 ). Frogs may be darker or lighter overall, as a result of handling, background coloration, temperature, or time of day. Upper surfaces of head and body light brown to tan with extremely variable dark brown markings that range from small spots or irregular blotches ( Fig. 6 a), through single transverse suprascapular bar, to a series of several oblique bars that extend laterally onto the flanks ( Fig. 6 e). Many specimens have an unbroken, cream to light tannish orange colored middorsal stripe highlighted by a suffusion of black pigment laterally ( Fig 6 b, d, e); the stripe may be narrower than the width of a finger or half as wide as the interorbital distance; others have a broad middorsal light tan field bordered laterally by a black margin ( Fig. 6 c), and a few have the dorsum marked with slightly irregular dark and light longitudinal stripes. Head in many individuals with a dark brown interorbital bar set off by tan color on snout ( Fig. 6 a, e); canthus rostralis usually marked with a strong dark stripe; upper surfaces of arms and legs the same color as dorsum; finger and toe discs pinkish tan; upper and lower legs and crus on some specimens have a hint of three to four light gray and tan alternating crossbands and on others there are three dark brown bands; throat of males white with black smudging or mottling, often white in females; belly and undersurfaces of legs heavily marked with dark pigment sometimes mottled as on throat, but lighter overall ( Fig. 6 f); individuals with a middorsal stripe also have a midventral, off-white streak ( Fig. 6 f); upper two-fifths of iris dirty gold color, lower three-fifths dark brown to black ( Fig. 6 f).

Color in preservative. Upper surfaces of head and body light gray to light tan with dark brown to black marks in various shapes from dashes to U’s, the dark marks paired on either side of the midline of the back in individuals with a dirty white, narrow, black bordered, middorsal stripe; usually a black interorbital triangle on the head set off by a tan rostrum; a prominent canthus rostralis with black stripe from eye to snout; upper arm uniformly dirty white, sometimes with a few black specks; forearm with one or two wide, alternating black and dirty white crossbands; hand and fingers with smaller black and white crossbands; finger and toe discs with a dark gray center, lighter distally; upper leg surface with three or four alternating dark and light bands, often faint or absent; crus, foot, and toes slightly banded as in the hands and fingers. Lower lip and throat black with dirty white speckling; belly dirty white in some females, dirty white and mottled or speckled with dark brown in males; posterior surface of thigh and inner surfaces of crus and legs uniformly rusty brown; palmar and plantar surfaces light gray to black.

Measurements of holotype (in mm). SL 26.6; HL 11.8; HW 10.8; EW 2.8; IOD 2.4; E 4.9; TY 1.3; C 17.5; FL 14.5.

Habitat and habits. Leafy shrubbery, branches, tree buttresses, exposed roots, and herbaceous ground vegetation usually> 0.5 m off the ground to 2 m high, in dense cloud forest. The most productive sites were the leafy banks of small cascades plunging down the steep sides of escarpments, often in the identical microhabitats of a species of arboreal toad, Oreophrynella sp. Vegetation near Falls Camp (05° 05.421’ N X 59 û 50.296’ W) along the stream, which steepened its incline and became a rocky, mossy, tumbling, cascading stream whose valley ran through huge sandstone boulders, covered in wet mosses and lichens. Also found on the leaves of understory vegetation in the cloud forest away from streams and cascades. This little frog seems to be a “leaf-sitter,” foraging for ants and insects on leaves off the ground. Individuals were seen within a few meters of P. dendrobatoides , also sitting on leaves. During the 2003 expedition on the eastern portion of the Wokomung Massif, every specimen of P. saltissimus had a distinctive stinky smell when handled, and a bittersweet taste. The skin secretions also made the back of the collector’s tongue feel affected for some minutes.

The sensation is difficult to describe, although numbness comes closest. During the 2006 expedition to the SW side of the massif (on the slopes and summit of Mt. Kopinang), DBM made a special effort to collect specimens of this species, smelling and tasting every one. Interestingly, individuals were quite variable in degree of noxiousness. Some were neither malodorous nor distasteful, but others distinctly smelled and tasted to varying intensities like those on the eastern side of the massif.

Distribution. Known only from the Wokomung Massif at elevations between 698 and 1560 m ( Fig 3 ).

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 6. Pristimantis saltissimus new species. a = plain or slightly spotted morph (43 % in a sample of 30); b = middorsally orange-striped morph (10 %); c = dorsally tan morph (17 %); d = thin, white-striped morph (10 %); e = dorsal views of the mottled morph (20 %) and thin, white-striped morph; f = ventral views of same morphs as in e. Note that the striping also occurs on the belly of the thin, white-striped morph.

FIGURE 7. Pristimantis saltissimus new species. Hand (left) and foot (right). USNM 563639 holotype. Black bars = 5.0 mm.