Pristimantis prometeii, Szekely, Paul, Cogălniceanu, Dan, Szekely, Diana, Paez, Nadia & Ron, Santiago R., 2016

Szekely, Paul, Cogălniceanu, Dan, Szekely, Diana, Paez, Nadia & Ron, Santiago R., 2016, A new species of Pristimantis from southern Ecuador (Anura, Craugastoridae), ZooKeys 606, pp. 77-97 : 80-89

Taxon classification Animalia ORDO FAMILIA

Pristimantis prometeii sp. n.

Holotype

(Figs 2-4). QCAZ 58044 (field no. SC-PUCE 47291), an adult female from Ecuador, Provincia El Oro, canton Piñas, Reserva Buenaventura, on the reserve’s Sendero del Perico de Orcés (3.6470°S, 79.7565°W; datum WGS84), 878 m above sea level, collected by Dan Cogălniceanu and Paul Székely on 14 September 2014.

Paratopotypes.

QCAZ 58045 (field no. SC-PUCE 47292), an adult female and QCAZ 58042 (field no. SC-PUCE 47289), an adult male (Fig. 5C, D) collected with the holotype; QCAZ 62540 (field no. SC-PUCE 51624), an adult female (Fig. 5A, B) and QCAZ 62541 (field no. SC-PUCE 51625), an adult male, same data as the holotype but collected by Dan Cogălniceanu on 13 September 2015.

Paratypes.

QCAZ 58056 (field no. SC-PUCE 47353), an adult male and QCAZ 58058 (field no. SC-PUCE 47355), an adult female from Ecuador, Provincia El Oro, canton Piñas, Reserva Buenaventura, close to Finca Ramírez (3.6311°S, 79.7618°W), 1082 m above sea level, collected by Dan Cogălniceanu on 7 September 2014; QCAZ 62547 (field no. SC-PUCE 51631), an adult female and QCAZ 62548 (field no. SC-PUCE 51632), an adult male from Ecuador, Provincia El Oro, canton Piñas, Reserva Buenaventura, Quebrada Oscura (3.6652°S, 79.7417°W), 948 m above sea level, collected by Dan Cogălniceanu on 15 September 2015.

Additional specimens.

Juveniles, QCAZ 58040 (field no. SC-PUCE 47287) (Fig. 5E, F) and QCAZ 58043 (field no. SC-PUCE 47290) with the same collecting data as the holotype.

Diagnosis.

This species is placed in the genus Pristimantis based on the general morphological similarity to other members of the genus (e.g. characteristic T-shaped terminal phalanges, toes without membranes, and Toe V longer than Toe III) and based on phylogenetic evidence (Fig. 1). Pristimantis prometeii is a medium-sized species distinguished by the following combination of traits: (1) skin on dorsum shagreen with numerous small tubercles; a low W-shaped ridge in the scapular region, usually with four larger warts on it; skin on venter areolate; discoidal fold weak; thoracic fold present; dorsolateral folds absent but with a longitudinal lateral fold from behind the tympanic fold along the 2/3 of the flank length; low mid dorsal fold with rows of small tubercles, especially on the head; (2) tympanic membrane and tympanic annulus prominent, its length about 40% of the length of eye; supratympanic fold obscuring upper and posterodorsal edges of tympanum; (3) snout short, subacuminate in dorsal view, rounded, slightly protruding in profile; canthus rostralis angular; (4) upper eyelid bearing one larger conical tubercle and numerous small tubercles, about 90% IOD in females and 85% IOD in males; cranial crests absent; (5) dentigerous processes of vomers prominent, triangular with 3 to 4 teeth; (6) males with a subgular vocal sac and vocal slits; (7) Finger I shorter than Finger II; discs on fingers broadly expanded, elliptical; (8) fingers bearing broad lateral fringes; (9) ulnar tubercles coalesced into low ulnar fold; (10) heel bearing one larger, conical tubercle and several smaller tubercles; outer edge of tarsus with row of small, conical tubercles; inner edge of tarsus bearing a low fold; (11) inner metatarsal tubercle broadly ovoid, about 5x ovoid outer metatarsal tubercle; supernumerary plantar tubercles present; (12) toes bearing broad lateral fringes; webbing absent; Toe V much longer than Toe III; discs elliptical, about same size as those on fingers; (13) in life, dorsum of various shades of brown, with or without white spots, blotches, or dark brown bars or reticulum; flanks cream, yellow, or green; venter cream with dark flecks and blotches; yellow blotches on the groin, anterior, and posterior surfaces of thighs; iris bronze with fine black reticulations and a median, horizontal read streak; (14) SVL 20.4-24.9 mm in adult males (22.4 ± 1.86 SD, n = 4) and 29.9-37.6 mm in adult females (32.7 ± 2.91 SD, n = 5).

Comparisons with other species.

Comparisons are based on molecular evidence to compare Pristimantis prometeii with close relatives and on morphologically similar species present in southern Ecuador and Northern Peru. The phylogenetically closest species are Pristimantis versicolor , Pristimantis phoxocephalus and Pristimantis riveti (Fig. 1). From these three Pristimantis phoxocephalus ( Lynch 1979) is the most similar. However, it is easily distinguished from Pristimantis prometeii by a fleshy vertical keel on the snout. Furthermore, Pristimantis phoxocephalus lacks tubercles on the upper eyelid, heel and tarsus, and the low W-shaped dermal ridge in the scapular region. Pristimantis riveti ( Despax 1911) differs from Pristimantis prometeii in having a heel without prominent tubercles (one prominent tubercle in Pristimantis prometeii ), smaller finger and toe discs, and W-shaped dermal ridge in the scapular region absent. In Pristimantis versicolor ( Lynch 1979), males lack vocal slits and vocal sacs (both present in Pristimantis prometeii ), the tarsus lacks distinct tubercles (tubercles present in Pristimantis prometeii ), lateral fringes are absent in toes (present in Pristimantis prometeii ), and the dorsum lacks the low W-shaped dermal ridge in the scapular region. Additionally, all these three Pristimantis species inhabit upper humid montane forest and subparamo, habitats at higher elevations than those of Pristimantis prometeii : 1800-3100 m, in Pristimantis phoxocephalus ( Lynch and Duellman 1997), 2.620-3.600 m in Pristimantis riveti ( Coloma et al. 2004) and 2500-3100 m in Pristimantis versicolor ( Frenkel et al. 2013). The related Pristimantis spinosus ( Lynch 1979) is also easily distinguished by the presence of cranial crests (absent in Pristimantis prometeii ), males lacking vocal slits and vocal sacs, and the coloration of groins and concealed surfaces of hind limbs which are black with white spots.

Among the few morphologically similar congeners from southern Ecuador, Pristimantis sternothylax ( Duellman and Wild 1993) can be distinguished by lacking prominent tubercles on the upper eyelid, having smooth ulnar surfaces, and heel and tarsus lacking tubercles and folds. Pristimantis buenaventura ( Arteaga et al. 2016) is somewhat similar but it is significantly smaller, and lacks prominent tubercles on the upper eyelid and heel. It also differs by having orange-red spots on the groins. Similar species in northern Peru include Pristimantis rhodoplichus ( Duellman and Wild 1993), Pristimantis wiensi ( Duellman and Wild 1993), and Pristimantis petrobardus ( Duellman 1991). Pristimantis rhodoplichus and Pristimantis petrobardus differ by lacking prominent tubercles on the upper eyelid. The lack of tympanic membrane readily distinguishes Pristimantis wiensi from Pristimantis prometeii . Both species also differ in dorsal coloration: green dorsum with scattered bronze and dark blotches in Pristimantis wiensi vs. brown dorsum in Pristimantis prometeii .

Description of the holotype.

Adult female (Fig. 3) with head slightly narrower than body, wider than long, head length 89% of head width, head width 36% of SVL; head length 32% of SVL; snout short (snout to eye distance 14% of SVL), subacuminate in dorsal view, rounded, slightly protruding in profile; canthus rostralis angular; loreal region flat; eye diameter notably greater than eye-nostril distance; nostrils slightly protuberant laterally; lips not flared; cranial crests absent; upper eyelid bearing one larger conical tubercle and numerous small tubercles, width of upper eyelid 94% of IOD; tympanic annulus prominent, round, its upper and posterodorsal part obscured by rounded supratympanic fold; tympanic membrane differentiated, visible; diameter of tympanum 41% of the length of eye; one larger and several low postrictal tubercles situated posteroventrally to tympanic annulus; choanae big, oval, not concealed by palatal shelf of maxillary; vomerine odontophores prominent, triangular, about 3x size of choana, separated medially by distance lower than width of odontophore; each otontophore has 3 to 4 teeth; tongue longer than wide, bilobate, posterior half not adherent to floor of mouth.

Skin on dorsum shagreen with numerous small tubercles; a low W-shaped dermal ridge is present in the scapular region, with 4 larger warts defining its corners (this trait is more visible in life, Fig. 2); thin, low mid dorsal fold starting at tip of snout and ending at cloaca, with rows of small tubercles, especially on the head (trait more visible in life, Fig. 2); dorsolateral folds absent; longitudinal lateral fold from behind the tympanic fold along the 2/3 of the flank length (trait more visible in life, Fig. 2); skin on throat, chest, belly, and ventral surfaces of thighs areolate; discoidal fold weak; thoracic fold present (trait more visible in life, Fig. 2); ornamentation in cloacal region absent.

Ulnar tubercles present, coalescing into low ulnar fold; outer palmar tubercle partially divided distally; thenar tubercle ovoid; subarticular tubercles prominent, round; supernumerary palmar tubercles rounded, smaller than subarticular tubercles; fingers bearing broad lateral fringes; Finger I shorter than Finger II; discs on fingers broadly expanded, elliptical; all fingers bearing pads well defined by circumferential grooves (Fig. 4).

Hind limbs moderately robust; tibia length 46.5% of SVL; foot length 40.7% of SVL; heel bearing one larger, conical tubercle and several smaller tubercles; outer edge of tarsus with row of small, conical tubercles; inner edge of tarsus bearing a low fold; inner metatarsal tubercle broadly ovoid, about 5x ovoid outer metatarsal tubercle; subarticular tubercles prominent, round; plantar supernumerary tubercles rounded, smaller than subarticular tubercles; toes bearing broad lateral fringes; webbing absent; discs on toes elliptical, about same size as those on fingers; toes with ventral pads well defined by circumferential grooves; relative length of toes I <II <III <V <IV; Toe V much longer than Toe III; tip of Toe III not reaching the distal subarticular tubercle on Toe IV; tip of Toe V extending to distal edge of distal subarticular tubercle on Toe IV (Fig. 4).

Coloration of holotype.

In life: dorsal background coloration tan ( Drab– 19), with dirty white spots and blotches of various sizes; flanks cream (Pale Buff– 1) with darker reticulum; venter and throat cream (Pale Buff– 1) with dark flecks and blotches; dorsal surface of hind limbs with faint darker transverse bars; ventral surfaces of hind limbs salmon (Light Flesh Color– 250); groin, anterior and posterior surfaces of thighs with faint yellow (Light Sulphur Yellow– 93) blotches; iris bronze with fine black reticulations and a median, horizontal red (Poppy Red– 63) streak which is wider at the edges of the eye.

In preservative: dorsal background coloration grayish brown; the white dorsal spots and blotches become more contrasting than in life; venter and throat dirty white with brown flecks and blotches; ventral surfaces of hind limbs brown with white flecks and blotches; the yellow blotches on the groin and anterior and posterior surfaces of thighs visible in life disappear in preservative.

Measurements of holotype (in mm).SVL 37.6; head width 13.6; head length 12.1; IOD 3.4; internarial distance 2.9; upper eyelid width 3.2; eye diameter 4.4; eye-nostril distance 3.9; snout to eye distance 5.3; eye to tympanum distance 1.8; tympanum diameter 1.8; femur length 16.8; tibia length 17.5; foot length 15.3; hand length 10.6; Finger I length 5.1. For morphometric variation, see Table 2.

Variation. Males are smaller than females (Table 2). The dorsal coloration in Pristimantis prometeii varies from brown, to green with or without dark brown bars or reticulum. The examined males have dark dorsal bars of various shapes, dark labial bars, dark canthal and supratympanic stripes and on the dorsal surface of hind limbs obvious dark transverse bars (Fig. 5). Males sometimes have a darker reddish-brown ( Vinaceous– 247) middorsal band, yellow (Sulphur Yellow– 80) or greenish (Light Lime Green– 113) flanks, and a white or brownish ( Tawny– 60) interorbital bar. The W-shaped dermal ridge in the scapular region is usually bordered by dark brown or whitish markings, more evident in males than females. The ventral coloration is very similar between females and males, the most important difference being the coloration of the subgular vocal sac in the males, which is yellow (Pale Greenish Yellow– 86) with black flecks.

Some females also have the W-shaped scapular dermal ridge dubbed by dark brown coloration and/or labial bars, canthal and supratympanic stripes like the males (Fig. 5). Two juveniles (QCAZ 58040, SVL = 10.4 mm and QCAZ 58043, SVL = 11.5 mm), identified based on the molecular data, have a darker reddish-brown (Kingfisher Rufous– 28) middorsal band, green (Apple Green– 104) flanks, dark dorsal bars of various shapes, brown (Kingfisher Rufous– 28) dorsal surface of the hind limbs with dark transverse bars and present labial bars, canthal and supratympanic stripes (Fig. 5). The low W-shaped dermal ridge in the scapular region, the thin middorsal fold and the incomplete longitudinal lateral fold are also visible. The venter is blackish with white flecks and spots and it is darker than in the adults.

The degree of tuberculation and development of dermal ridges on the dorsum and flanks is usually more evident in males than females. However, the tubercles and dermal folds are difficult to observe in preservative. The low W-shaped dermal ridge in the scapular region, the thin mid dorsal fold, the incomplete longitudinal lateral fold and the thoracic fold are easily observable in life but can be very difficult to notice in the preserved specimens.

Etymology.

The specific name is a noun in the genitive case and refers to the Prometeo program of Secretaría de Educación Superior, Ciencia, Tecnología e In novación, Republic of Ecuador (SENESCYT) through which Dan Cogălniceanu and Paul Székely received funding for their research in southern Ecuador.

Distribution and natural history.

Pristimantis prometeii is known from three closely located sites at Reserva Buenaventura (Fig. 6), Provincia El Oro, southwestern Ecuador, at elevations between 878 and 1082 m (Fig. 7). Most of the specimens were encountered at night, usually after rains, perching on leaves 10 to 100 cm above the ground. No calling male was found. Two specimens (QCAZ 58056 and QCAZ 58058) were collected during the day in small bromeliads between 2.0 and 2.5 m. All specimens were found in September 2014 and 2015 and additional surveys carried out in 2016 failed to encounter this species. All individuals were found in fairly well-preserved forest areas, near the reserve’s trails or in the vicinity of streams. One of the paratopotypes (QCAZ 58045), an adult female, was missing the right foreleg. Sympatric frog species at the type locality in Reserva Buenaventura include Pristimantis achatinus and Pristimantis subsigillatus as well as Epipedobates anthonyi , Hyloxalus infraguttatus , Espadarana prosoblepon , Hypsiboas pellucens and an undescribed species of Hyloscirtus .

Conservation status.

Pristimantis prometeii sp. n. is only known from three nearby sites in Reserva Buenaventura, Provincia El Oro. Given the scarcity of information on the distribution of the new species, we recommend Pristimantis prometeii to be considered as Data Deficient following IUCN’s Red List categories ( IUCN 2001).