Hypsiboas tepuianus, Barrio-Amorós & Brewer-Carías, 2010

Barrio-Amorós, César L. & Brewer-Carías, Charles, 2010, Venezuelan Guayana, with the description of five new species, Zootaxa 1942, pp. 1-68 : 28-33

Hypsiboas tepuianus sp. nov.

( Figs. 10A, B, C )

Tepui tree frog, Rana tepuyana

“ Hyla benitezi: Donnelly & Myers, 1991:11 ; Heyer, 1994a:497; Gorzula & Señaris, 1999:27; Hypsiboas benitezi: Faivovich et al. 2005: 86 .”

Holotype. EBRG 4653 , an adult female from the southern slope of Sarisariñama-tepui , Locality VI, Estado Bolívar, Venezuela (4º25’ N, 64º7’ W), elev. 420 m, collected by César L. Barrio-Amorós on 22 March 2002.

Paratypes. Four paratypes (all males, EBRG 4654–56 , 4877 ) with the same collection data as the holotype. EBRG 20–21 from Río Marajano , Jaua-tepui, Estado Bolívar, Venezuela, elev. 1800 m, collected by P.A .

Summit Camp I (elev. 1030 m), Guaiquinima , Estado Bolívar, Venezuela, collected by M.A. Donnelly and C.W. Myers on 24 February 1990 .

Etymology. The specific name is an adjective derived from tepui + - anus (tepui is a Pemon word meaning mountain, and applied to those table mountains typical from southern Venezuela; and – anus is the suffix meaning “belongig to”).

Diagnosis. Hypsiboas of the H. benitezi group (sensu Faivovich et al. 2005) with (1) dorsal skin smooth to weakly shagreeneded, ventral skin smooth to weakly granular; (2) tympanum indistinct, barely evident in some individuals; (3) snout rounded to truncate in dorsal view, rounded in profile; canthus rostralis distinct, rounded; (4) choanae moderately large, elliptical; dentigerous processes of the vomers distinct, / \ -shaped to arched, with 7–16 teeth on each process; tongue not free, wide, round, slightly cordiform; (5) vocal slits reaching from midlength of tongue to the posterior edge of jaw; (6) FI = FII; (7) fingers lacking lateral fringes; (8) ulnar tubercles absent or almost indistinct; (9) calcars absent; (10) two metatarsal tubercles, inner elliptical, outer minute, almost indistinct; (11) toes lacking lateral fringes; (12) in preservative, dorsal ground color pale yellow to gray and various shades of brown (holotype darkest specimen), with transverse dark brown lines or bars, or reticulum, or dorsolateral stripes; venter immaculate white; in life, dorsum bright yellow with brown markings, or brown with gray markings, or dark brown with yellow dorsolateral stripes; fingers, toes, and webbing reddish orange; (13) SVL 30–36 mm in males, 34.5–47.7 mm in females.

Among the Hypsiboas inhabiting the Guayanan region, H. tepuianus may be confused with similar, brown-colored species but can be distinguished from them as follows (characters of H. tepuianus in parentheses). Hypsiboas benitezi , which most closely resembles H. tepuianus , is larger in size, has a ridge of discrete ulnar tubercles (absent or almost indistinct), and has a different advertisement call. Hypsiboas lemai has a yellow dorsal ground color, but can be brown during the day (yellow to dark brown), FI <FII (FI = FII), and all of its fingers are basally webbed (webbing absent between FI and FII). Hypsiboas rhythmicus has cream fingers, toes, and webbing (reddish orange), a golden iris in life (grayish to bronze), small discs on fingers and toes (large), an advertisement call consisting of a single note with dominant frequency at 3260–3450 Hz (2–5 notes at 2500 Hz; Fig. 10D ), and it calls from undersides of leaves (calls from over leafs and sticks). Hypsiboas jimenezi and H. sibleszi are both mainly green in life (brown to yellow). Myersiohyla loveridgei has a distinct tympanum, 50% ED (indistinct, 33% ED), a distinct supratympanic fold (indistinct), a distinct transverse fold on the heel (absent), flanks mottled with white, and an orange coloration in life (mottling absent). Hyla warreni , a species incertae sedis among South American hylid frogs in view of the revision of Hylidae by Faivovich et al. (2005), has a distinct tympanum (almost indistinct), an axillary membrane (absent), and a cream venter with brown spots (immaculate white; Duellman and Hoogmoed 1992).

Description. Size moderate, with SVL in four males 31.8–36.0 mm (mean 33.8 mm), in four females 38.7–47.7 mm (mean 42.8 mm). Body relatively robust; head large (HeL = 31–35% SVL), slightly wider than long, slightly wider than body; IOD = 34–36% HW; upper eyelid broad (UEW = 68–82% IOD); snout rounded in dorsal view, sometimes truncate, rounded in profile, long (distance from anterior border of eye to tip of snout 48–52% HeL); interorbital and internarial areas flat, canthus distinct, rounded; loreal region slightly concave; lips not flared; supratympanic fold weakly defined; tympanum indistinct, TD = 32–39% ED; palpebral membrane unpigmented; tongue round, slightly cordiform, not free; vocal slits present, extending from midlength of tongue to posterior edge of jaw; dentigerous process of vomers / \ -shaped to arched, with 7–16 teeth on each, depending on individual size.

Forearms moderately robust; axillary membrane absent; ulnar tubercles absent (very weak protuberances in some specimens); fingers long with round, broad (wider than fingers) terminal discs; disc on FII slightly wider than that on FI, in both cases more than twice of TD; FI = FII (FI just slightly longer than FII in holotype, EBRG 4654–55, EBRG 4877, EBRG 21; FII slightly longer than FI in EBRG 20, 4656; FI = FII in EBRG 3435); webbing between FI and FII basal (e.g., MBUCV 6704) or absent (e.g., holotype), webbing formula for the rest of the hand II 2–3 III 2 2/3–2 IV; fingers with or without lateral fringes; subarticular tubercles thenar tubercle large, elliptical; enlarged pollex with hidden prepollical spine, larger and more prominent in males than in females.

Hind limbs long (heels extending beyond snout in males and smaller specimens but only reaching the eyes in females); tarsal fold absent; toes long; extensively webbed; modal webbing formula I 1–1 II 1–1 III 1– 1½ IV 1½–1 V; inner metatarsal tubercle flat, oval; outer metatarsal tubercle nearly indistinct, round, or absent; subarticular tubercles moderately large, round, simple; supernumerary tubercles absent.

Skin of sides of the head and flanks granular to smooth, that on dorsum of head and body smooth to shagreened; chest and throat smooth; belly finely to coarsely granular; ventral surfaces of limbs granular; cloacal opening directed posteriorly at upper level of thighs; supracloacal flap short; anal ornamentation consists of a series of white tubercles on both sides of the vent opening in males.

In life, the flanks and dorsal surfaces of the head, body, and limbs of the female holotype were brown with dark brown reticulations; distinct yellow dorsolateral stripes, extending from the tip of the snout almost to the groin, and the fingers and toes were reddish orange ( Fig. 10A ). The dorsum in a male (EBRG 4654; Fig. 10B ) was bright yellow with a fine dark brown reticulation; dark brown canthal and supratympanic stripes were continuous with a narrow brown dorsolateral stripe, that was not as conspicuous as the yellow stripe in the holotype; the fingers and toes were pale orange. Another male (EBRG 4655; Fig. 10C ) was brown dorsally, with black wide transverse stripes, and narrow lines; its venter was pink.

In preservative, the holotype is reddish brown with darker brown reticulations on the dorsum; the dorsolateral stripes are dirty white, and the fingers and toes are pale yellow. A specimen from Guaiquinima (MBUCV 6701) is a small male with the same pattern as the holotype. A female (EBRG 3435) from Jauatepui has bright white canthal stripes that continue onto the edges of the upper eyelids. Conspicuous or indistinct brown transverse bars are present on the arms and hind limbs in all specimens, except in MBUCV 6704 from Guiaquinima, in which the dorsum is pale brown dorsum with indistinct transverse bars on the body. Somewhat more distinct transverse bars are present on the dorsum in MBUCV 6702. The dorsum in EBRG 4654, MBUCV 6703, and 6706 is pale yellow with dark brown reticulations. The dorsum in MBUCV 6705 is brown with many melanophores and indistinct darker brown transverse bars, whereas EBRG 4655–56 and EBRG 4877 are gray with dark gray transverse bars. Variation is independent of geography.

Natural history. Activity.—All specimens collected were active at night; calling males were sitting on branches and leaves about 0.5 m above the water. One female was in the spray zone of a waterfall. In Guaiquinima, Donnelly and Myers (1991) also report the species (as Hyla benitezi ) to be perched at night 1–2 m above water or on rock faces near small waterfalls. The absence of the right foot in EBRG 4877 may be the result of predation.

Vocalization.—Males called from perches in bushes, 0.5–1.5 m above streams. Our recording, made beetwen 1900–2000 h, temperature 23ºC, are of low quality because of the background noise from the stream. Several males produced calls with three notes. The illustrated call ( Fig. 10D ) has duration of 269 ms, and the first note is 50 ms long. The dominant frequency is 2500 Hz (fundamental 1700 Hz). The call show harmonics at 4900 and 7500 Hz; these are not evident in the audiospectrograms in Donnelly and Myers (1991) or Heyer (1994 a). Another call of five notes (not illustrated) had a frequency of 2500 Hz. As noted by Myers and Donnelly (1997), the calls of frogs from Tamacuari (western part of the Venezuelan Guayana Shield), Guaiquinima, and Pacaraima, and now from Sarisariñama (eastern part), can be well differentiated. The only recording from a western population (Tamacuari; frequency mainly at 1880 Hz) has a lower dominant frequency that lies 300–480 Hz lower than recordings from Guaiquinima and Pacaraima (2360 Hz and 2000–2180 Hz respectively). The recording from Sarisariñama has the highest dominant frequency at 2500 Hz and also has two harmonics at higher frequencies.

At an elevation of 1600 m on Jaua-tepui, Hypsiboas tepuianus occurs sympatrically with H. rhythmicus

Distribution. Hypsiboas tepuianus ranges through lowlands and uplands (400–1600 m) of the Venezuelan Guayana and extreme northern Brazil (Vila Pacaraima, Heyer 1994a) east of the Sierra de Maigualida-Parima. The known localities ( Fig. 11 ) include Auyan-tepui (C. Señaris, pers. comm.) and the upper Río Ambutuir ( Gorzula and Señaris 1999), Guaiquinima ( Donnelly and Myers 1991), Sarisariñama-tepui (this paper), Jauatepui ( Gorzula and Señaris 1999; Señaris and Ayarzagüena 2002), and Quebrada de Jaspe ( Gorzula and Señaris 1999). Hypsiboas benitezi is known from several localities ( Fig. 11 ), all west of Sierra de Maigualida- Parima, including Duida ( Rivero 1961), Marahuaka ( Rivero 1971), Tamacuari ( Myers and Donnelly 1997), and Apepada, upper Río Ventuari (EBRG 1897).

Remarks. Hypsiboas tepuianus apparently has a mental gland (sensu Faivovich et al. 2006). We did not consider this character in the diagnosis or description, however, because we consider that it is very subjective, and not easy to determine. For instance, while it is easily identificable in Hyloscirtus colymbus , H. palmeri and H. albopunctulatus (see Fig 4 in Faivovich et al. 2006), it is much less obvious in Hypsiboas nympha and H. lemai (same Fig 4 ; Faivovich et al. 2006), and to us, an object of subjective appreciation. In two specimens of H. lemai examined (to be deposited in EBRG), the senior author could not distinguish the mental gland. In two more specimens of H. jimenezi , he either could see any gland (in accordance with Señaris and Gorzula 2006). Examining the mental zone of male paratypes of H. tepuianus , is possible to discern a whitish quadran-

Examined material. Hypsiboas benitezi .— VENEZUELA: Estado Amazonas, Apepada, upper Río Ventuari , EBRG 1897 .

Hypsiboas tepuianus .— VENEZUELA: Estado Bolívar, Río Marajano , meseta de Jaua, EBRG 20–21 ; Jaua (4º49’55’’N, 64º25’64’’W), elev. 1600 m, EBRG 3435 ; Guaiquinima , MBUCV 6701–06 (former AMNH 133849–54 ) .

Figures

FIGURE 4. (a) adult female individual of Anomaloglossus moffetti sp. nov. Details of external characteristics drawn from the paratype of Anomaloglossus moffetti sp. nov. EBRG 6465, including lateral (b) and dorsal (c) views of the head, a palmar view of the left hand (d) and a plantar view of the left foot (e). Scale bars are 1 mm long. Note that the discs on the tips of fingers III and IV and toe V are curved, giving the impression of a finger shorter than it actually is. In the artist

FIGURE 10. Three individuals of Hypsiboas tepuianus sp. nov., showing color variation of the species. Shown are (a) the female holotype (EBRG 4653), and two male paratypes, EBRG 4654 (b) and EBRG 4655 (c). (d), advertisement call, recorded at 23 ºC.

FIGURE 11. Distribution of Hypsiboas tepuianus sp. nov. (dots) and H. benitezi (squares) in southern Venezuela. The circle indicates Sarisariñama, the type locality of H. tepuianus.