Psychrophrynella teqta, Riva, Ignacio De La & Burrowes, Patricia A., 2014

Riva, Ignacio De La & Burrowes, Patricia A., 2014, A new species of Psychrophrynella (Anura: Craugastoridae) from the Cordillera Real, Department La Paz, Bolivia, Zootaxa 3887 (3), pp. 459-470 : 460-468

Psychrophrynella teqta , sp. nov.

( Figs. 1–2 , 5 )

Holotype. CBF 6725 (field tag 4421), an adult female from Pablo Amaya, Provincia Larecaja, Departament La Paz, Bolivia (15º58’52.55” S, 68º12’19.6” W), 3700 m.a.s.l., collected on 6 November 2012 by Ignacio De la Riva and Patricia A. Burrowes.

Paratypes. CBF 6726 (4415) and MNCN 45702–3 (4413, 4414), adult males; CBF 6727–8 (4417, 4422) and MNCN 45704–5 (4416, 4418), adult females; and CBF 6729 (4420) and MNCN 45706 (4419), juveniles, same data as the holotype.

Diagnosis. A member of Craugastoridae assigned to the genus Psychrophrynella based on biogeographical and morphological grounds. Two other genera of Holoadeninae (sensu Padial et al. 2014) occur in Bolivia: Noblella and Oreobates . Noblella has terminal phalanges narrowly T-shaped, discs and distal circumferential grooves present distally, and tips of at least toes III and IV acuminate (terminal phalanges knob-shaped, circumferential grooves absent, and tips of all digits rounded in Psychrophrynella ); Oreobates has dentigerous processes of vomers prominent (absent in Psychrophrynella ) ( Duellman & Lehr 2009). Psychrophrynella teqta is diagnosed by the following combination of characters: (1) medium size (maximum SVL 27.8 mm), body robust, legs short (average TL + FL between 69.8–75.7% SVL; n = 8); (2) tympanic membrane absent, tympanic annulus present, visible under the skin; (3) first finger slightly shorter than second; (4) tips of digits slightly swollen, not expanded laterally; (5) webbing of toes and lateral fringes absent; (6) two metatarsal tubercles, tarsal fold absent; (7) dorsal skin and flanks shagreen to pustulate; dorsolateral folds irregular, reaching midbody; ventral skin areolate; (8) snout rounded in dorsal view and in profile; (9) color on dorsum variable, from dark brown to beige, with or without irregular cream, reddish-brown blotches; (10) color on venter variable, from dark brown to cream, with a pattern of irregular blotches cream, yellow, or gray.

Psychrophrynella teqta is distinguished from other species in the genus for which the call is known, by its pulsed call. Regarding morphology and coloration, the new species is superficially similar to P. wettsteini (Parker) and P. condoriri ( De la Riva, Aguayo and Padial), which furthermore are species whose type localities are geographically close to that of P. teqta . The new species is distinguished from P. wettsteini mostly by its smaller size (maximum SVL in P. wettsteini 33.4 mm) and shorter legs (TL + FL> 80% SVL in P. wettsteini ); the color pattern in P. wettsteini is mostly gray or reddish-brown above with or without pale spots and ventrally cream with reddish-brown spots or reticulations, while in P. t e q t a coloration is extremely variable and often there are reddish and yellow blotches, which are never present in P. wettsteini . From P. condoriri , the new species differs mostly by having dorsal skin shagreen or rugose (mostly smooth in P. condoriri ), and a variable color pattern both on dorsum and venter, including reddish and yellow blotches (dorsum brown with diffuse darker areas, venter gray with brown markings). The small species P. chacaltaya ( De la Riva, Padial and Cortéz) is found in the upper Zongo Valley, not far from the type locality of P. teqta , and it is easily distinguishable from the new species by being much smaller (maximum SVL 20.4 mm), and having a different color pattern, consisting of dorsum dark grayish-brown with darker marks and venter uniformly cream or brown with irregular brown blotches.

Description of the holotype. Body robust; dorsal skin covered with many small pustules, more abundant on flanks, posterior part of body, and upper surface of thighs; a pair of dorsolateral folds reaching midbody (pustules and dorsolateral folds barely visible in preservative for changes in skin texture); ventral skin areolate; no thoracic or discoidal fold; a pelvic patch on lower surfaces of thighs, rugose, slightly swollen. Head wider than long, its width 35.6% of SVL; head length 27.9% of SVL; snout moderately long, slightly rounded in dorsal view and in profile; nostrils not protuberant, directed laterally, closer to snout than to eyes; canthus rostralis poorly marked, straight, convex in dorsal view and in profile; eye-nostril distance 84.6% of eye length; loreal region barely concave, interorbital region flat, lacking cranial crests; tubercles on upper eyelid absent; tympanic membrane absent, two lower thirds of tympanic annulus slightly noticeable under the skin; supratympanic fold short, weak, poorly marked; no postrictal tubercles or glands; tongue large, oval; choanae oval, small, widely spaced; vomerine odontophores absent. Limbs moderately short; tips of digits slightly swollen, not expanded laterally; ulnar tubercle and fold absent; inner palmar tubercle single, oval, poorly defined, smaller than round outer; fingers not fringed; subarticular tubercles round, poorly defined; supernumerary tubercles, round, small; first finger slightly shorter than second, relative length of fingers 1<2<4<3; tibia length 34.8% of SVL; tarsus lacking tubercle and fold; inner metatarsal tubercle oval, larger than round, poorly defined outer; plantar surface smooth, no supernumerary tubercles; subarticular tubercles round, slightly swollen; toes moderately long and slender, not webbed or fringed; relative length of toes 1<2<3<5<4; foot length 37.9% of SVL.

Measurements (in mm) of the holotype. SVL 26.1; HL 7.3; HW 9.3; IND 2.3; END 2.2; ED 2.6; TL 9.1; FL 9.9.

Color. In life, upper surfaces of body, head and limbs black; a few pinky-cream, irregular blotches on dorsum and upper parts of flanks; creamy-yellow stripes on the upper edge of canthus rostralis, converging on the snout and forming and inverted V from above; upper lip and post-commissural areas pale yellow; diffuse brown areas on upper surfaces of forearms; venter and throat black with large, creamy-yellow blotches forming an irregular pattern, becoming greenish-beige on belly; a blotch of this same color on the lower surface of each limb; lower surface of thighs pale brown, with a reddish-brown, rugose pelvic patch; ventral surfaces of digits and inner part of palms fleshy; iris greenish-brown, heavily reticulated in black, especially on the lower two thirds. In preservative, dorsum, head, and upper parts of the extremities dark brown, with irregular areas slightly paler; gray, cream, and pinky cream irregular blotches on dorsolateral areas and flanks; gray stripes bordering the canthus rostralis above; upper lip and post-commissural area pale cream, with a fine dark brown line on the rim of the lip; diffuse brown areas on upper surfaces of forearms; throat and venter dark brown, almost black, with large cream blotches forming an irregular pattern; lower thighs pale brown; ventral surfaces of digits and inner part of palms pale cream.

Variation. Morphometric variation is given in Table 1 . Males lack nuptial pads, and have small vocal slits and a rugose, moderately developed, subgular vocal sac. Variation in color pattern is highly remarkable ( Fig. 2 ; notes based on coloration in life). The male MNCN 45702 has upper parts, throat and lower surfaces of limbs dark brown; there is a greenish-beige line along the lower jaw; the venter is reddish-brown with large, irregular, bluishgray blotches. The male MNCN 45703 is pale brown above, with flanks reddish-beige with a reticulated pattern of dark brown dots and blotches, all interconnected; there is a black supratympanic stripe; the throat is bluish-gray, densely pigmented with dark brown; the venter is dark brown with small, scattered, irregular dark brown blotches. The male CBF 6726 is pale brown above, with a black vertebral stripe and black irregular blotches forming an Xshaped dorsal pattern; there is a black line from the tip of the snout to the shoulder, across the canthus rostralis, the eye, and the supartympanic region; the flanks have an irregular pattern of black and golden-beige blotches; the venter is bluish-gray with large black blotches, and the throat is dark brown with bluish-gray flecks. Two large females—CBF 6727 and MNCN 45705—are, overall, similar to the holotype, but the former has a fine, greenishbeige vertebral stripe, and the lower parts of head and body are black with irregular, greenish-beige blotches (forming a longitudinal stripe on the throat); there are orange-beige blotches over the insertion of the forearms and on the posterior part of the flanks; a reddish line is present along the posterior surfaces of thighs, meeting on the cloacal region, where they form a heart-like shape. The female CBF 6728 is uniformly dark brown, almost black above, with irregular, reddish-brown blotches on dorsum and flanks; the throat is reddish-beige and the venter is greenish-beige with black. A specimen with a remarkable pattern is the female MNCN 45704, which is olivebrown above, and has reddish flanks with a finely reticulated, brown pattern; there is a fine, beige vertebral stripe starting on the tip of the snout; the throat, chest, and venter are greenish-beige with broad, reticulated, dark brown blotches; the same reticulated pattern appears on the lower surface of limbs, encircling reddish blotches; there is a reddish-brown line along the posterior surface of the thighs. The two juveniles collected are equally variable. MNCN 45706 is pale reddish-brown above with diffuse areas olive-brown, and the flanks are dark brown with pale red spots on the inguinal region; the toe tips are red. CBF 6729 is dark brown dorsally, with a fine, pale beige vertebral stripe; there is a fine reddish line along the posterior surface of thighs, converging at the cloacal region, forming a heart-like shape.

Distribution and ecology. This species is known only from the type locality ( Fig. 3 ). The locality of Pablo Amaya is surrounded by agricultural fields and pastures for llamas, leaving very little suitable habitat for Psychrophrynella frogs. The new species was on the more humid slopes passing the village, midway between the old road and the small river that flows along the valley. Individuals were found under stones by day. One individual (MNCN 45704) was on the bank of a narrow, small canyon, and the rest were under the scattered stones pertaining to the ruins of an old construction ( Fig. 4 ), which created a micro-environment with humidity and vegetation highly suitable for the species. No other species of anurans were found in syntopy. The type locality of P. condoriri is 5.25 km to the northwest of Pablo Amaya, that of P. wet tstei ni is 45 km to the southeast, and P. cf. chacaltaya occurs 25.5 km also to the southeast, in the upper Zongo Valley.

Natural history. Reproduction data on species of Psychrophrynella are not easy to gather. So far, only the eggs of P. w e t t s t e i n i and P. illampu ( De la Riva, Reichle and Padial) had been observed or photographed [ Ergueta 1993; De la Riva 2007; recently, nests of P. illimani ( De la Riva and Padial) were found and photographed by A. Muñoz and colleagues (A. Muñoz, in litt.)]. We found two clutches of P. teqta under stones, each of them guarded by a male occupying a small chamber. The first clutch contained 41 well-developed eggs (average diameter 5.11 mm, n=5; Fig. 5 ), containing embryos that moved frequently inside the egg capsule; the guarding male (MNCN 45703) was quite small (23.5 mm SVL). This clutch proved to be difficult to extract from the ground, for it was deeply intermingled with small, very slender grass roots. The second clutch had 28, smaller, yellowish-white eggs (average diameter 4.74 mm, n=5). In both cases, the males remained on or beside the eggs, presumably offering some type of parental care. They had the snout slightly protruding, of a translucent gray color, different from the rest of the head; this probably indicates certain burrowing activity to construct and maintain the chambers where they guard the clutch. The holotype had large, developed oviducts but no female among our sample showed oviductal eggs.

Advertisement call. Calls of Psychrophrynella are remarkably similar across species, and most calls consist of a simple, tonal, rather short, high-pitched note [so far, the most divergent call is that of P. saltator ( De la Riva, Reichle and Bosch), consisting of series of 7–36 short notes; see De la Riva 2007]. At the time of collecting P. teqta (05–07 h pm) some frogs were calling. Surprisingly, calls were pulsed, not tonal. Thus, it was very important to capture a voucher calling male in order to be sure that the recorded call indeed belonged to the new species. The voucher male (MNCN 45702) was in the middle of a thick mass of moss, over a large rock. At an air temperature of 10.8ºC and a relative humidity of 77%, this male emitted pulsed calls consisting of a simple note with an average duration of 270 ms (n=8; Fig. 6 ), uttered in irregular series of several calls. Based on the total time of recording, the overall call rate is approximately 6.5 calls/minute (average interval between calls, 2,365 seconds; n=6). Each call has 16–19 pulses of variable duration, being the first pulses shorter. For example, the first pulse lasts, on average, 8 ms, while the last pulse has an average duration of 26 ms. The pulse amplitude is also progressively higher along the call, with a maximum at approximately 221 ms from the onset of the call (i.e., call rise time 82% of call duration). The spectral structure of this advertisement call is characterized by an average dominant frequency of 2.2 kHz, corresponding with the fundamental frequency of the signal and lacking frequency modulation. The call shows 3–5 apparent harmonics, of which the first one accounts for an average of 95% of the total signal energy ( Fig. 6 ).

Etymology. The specific name is a mostly arbitrary combination of letters that the authors do like.

Figures

FIGURE 1. Dorsolateral and ventral view of the living holotype of Psychrophrynella teqta sp. nov. (CBF 6725; SVL 26.1 mm).

FIGURE 2. Variation in color pattern of Psychrophrynella teqta sp. nov. Dorsolateral and ventral views of A: MNCN 45704 (female; SVL 27.8 mm); B: CBF 6726 (male, 23.6 mm SVL); C: CBF 6727 (female, 27.2 mm SVL); D: CBF 6728 (female, 25.8 mm SVL).

FIGURE 3. Map of northern Bolivian Andes showing the distribution of Psychrophrynella teqta sp. nov. (star), and general aspect of the type locality.

FIGURE 4. Ruins of old local constructions, which create an optimal microhabitat for Psychrophrynella teqta sp. nov.

FIGURE 5. Male of Psychrophrynella teqta sp. nov. (MNCN 45073) guarding eggs.

FIGURE 6. Advertisement call of Psychrophrynella teqta sp. nov. Air temperature at the time of recording, 10.8 ºC. Above, oscillogram and power spectra (power spectra analysis bandwidth: 15 Hz). Below, spectrogram and oscillogram (spectrogram analysis bandwidth: 94 Hz).

Tables

TABLE 1. Morphometrics of Psychrophrynella teqta sp. nov. Means followed by ranges in parentheses. For abbreviations, see text.

Character	Adult Females (n=5)	Adult Males (n=3)
SVL	26.8 (25.8–27.8)	23.2 (22.7–23.6)
HL	7.1 (6.7–7.5)	6.2 (6.1–6.4)
HW	8.9 (8.4–9.4)	8.0 (7.4–8.6)
IND	2.2 (1.9–2.3)	1.9 (1.8–2.2)
END	2.1 (2.1–2.2)	1.7 (1.5–1.9)
ED	2.4 (2.2–2.6)	2.1 (1.9–2.2)
TL	9.4 (9.1–9.7)	8.1 (7.7–8.6)
FL	10.2 (9.7–11.0)	9.0 (8.7–9.2)
HL/SVL	0.26 (0.25–0.27)	0.26 (0.26–0.27)
HW/SVL	0.33 (0.31–0.35)	0.34 (0.31–0.37)
END/ED	0.90 (0.84–0.95)	0.82 (0.68–0.94)
TL/SVL	0.34 (0.34–0.36)	0.34 (0.33–0.36)
FL/SVL	0.37 (0.35–0.39)	0.38 (0.38–0.39)