Pristimantis amaguanae, Ron & Carrión & Caminer & Sagredo & Navarrete & Ortega & Varela-Jaramillo & Maldonado-Castro & Terán, 2020

Ron, Santiago R., Carrion, Julio, Caminer, Marcel A., Sagredo, Yerka, Navarrete, Maria J., Ortega, Jhael A., Varela-Jaramillo, Andrea, Maldonado-Castro, Gabriela A. & Teran, Claudia, 2020, Three new species of frogs of the genus Pristimantis (Anura, Strabomantidae) with a redefinition of the P. lacrimosus species group, ZooKeys 993, pp. 121-155 : 121

Pristimantis amaguanae sp. nov. Figures 5 , 6 , 7

Material.

Holotype. QCAZ 39274 (field no. VH 1105; Figs 5 - 7 ), adult female from Ecuador, Provincia Pastaza. Surroundings of Villano, AGIP oil camp, K10, Unit 3. (1.4727°S, 77.5359°W), 430 m above sea level, collected by Edwin Carrillo, Galo Díaz, Yadira Mena and Fernando Ayala on 12 October 2008. Paratype (1). QCAZ 39275, adult male collected in amplexus with the holotype.

Suggested common name.

English: Amaguaña’s Rain Frog. Spanish: Cutín de Amaguaña.

Diagnosis.

A species of Pristimantis characterized by the following combination of characters: (1) skin on dorsum shagreen with conical tubercles, skin on venter areolate with light green warts on the chest; discoidal fold absent; dorsolateral folds absent (Fig. 5 ); (2) tympanic membrane and tympanic annulus present, its dorsoposterior border converges with supratympanic fold; (3) snout acuminate in dorsal, protruding in lateral profile, with rostral papilla; (4) upper eyelid with several small conical tubercles; cranial crests absent; (5) dentigerous processes of vomers absent; (6) male having vocal slits, nuptial pads absent; (7) finger I shorter than finger II; discs of digits expanded, rounded (Fig. 6 ); (8) fingers with lateral fringes; hyperdistal subarticular tubercles present; (9) ulnar tubercles present, low and rounded; (10) heel bearing conical tubercles varying from prominent to inconspicuous; inner tarsal fold absent; (11) inner metatarsal tubercle ovoid, elevated, five times the size of round outer metatarsal tubercle; supernumerary plantar tubercles present; (12) toes with narrow lateral fringes; basal toe webbing absent; toe V much longer than toe III (disc on toe III reaches the proximal border of the penultimate subarticular tubercle on toe IV, disc on toe V reaches the distal subarticular tubercle on toe IV); hyperdistal subarticular tubercles present; toe discs as large as those on fingers (Fig. 6 ); (13) in life, dorsal surfaces of body and limbs olive green or olive brown with black markings; canthal stripe and supratympanic fold black; lips cream with black bars; flanks cream with one broad oblique black bar; chest light green with greenish cream warts; belly yellowish white; iris bronze to reddish copper with black reticulations (Fig. 5 ); (14) SVL in adult female 20.4 mm (n = 1), in adult male 16.3 mm (n = 1).

Comparison with other species.

In this section, coloration refers to live individuals unless otherwise noticed. The coloration of Pristimantis amaguanae resembles that of P. bromeliaceus and P. petersi (Fig. 5 ). Pristimantis amaguanae can be easily recognized by the presence of transversal dark bands in the hindlimbs (absent or faint in P. bromeliaceus and P. petersi ) and the absence of discoidal fold (present in P. bromeliaceus and P. petersi ). Pristimantis amaguanae further differs from P. bromeliaceus by its smaller adult size (female SVL = 20.4 mm, males SVL = 16.3 mm vs. P. bromeliaceus female SVL = 23.0-28.5 mm, male SVL = 16.7-22.8 mm; Lynch and Duellman 1980). Another small, green Pristimantis from the Amazon basin is P. paululus . The new species differs by having more tuberculate dorsal skin, discoidal folds absent (folds prominent in P. paululus , Lynch 1974), and scattered enlarged light green warts in the venter (small white points in P. paululus ; Lynch 1974). Pristimantis pseudoacuminatus differs by having a truncate snout in profile (acuminate in P. amaguanae , Fig. 7 ) and by having a lighter and more uniform coloration in preservative.

Description of the holotype.

Adult female (QCAZ 39274). Measurements (in mm): SVL 20.4; tibia length 9.5; foot length 8.7; head length 8.7; head width 7.7; eye diameter 2.8; tympanum diameter 1.1; interorbital distance 2.5; upper eyelid width 1.9; internarial distance 2.0; eye-nostril distance 2.3; tympanum-eye distance 0.8. Body slender; head slightly longer than wide, wider than body; snout acuminate in dorsal view, protruding in lateral profile, with rostral papilla; canthus rostralis distinct, curved in dorsal view; loreal region concave; interorbital space flat, no cranial crests; eye large, protuberant; upper eyelid bearing numerous small tubercles; tympanic membrane and annulus distinct, rounded in shape, with supratympanic fold partially covering upper and posterodorsal edges; choanae large, rounded, not concealed by palatal shelf of maxillary arc; dentigerous processes of vomers absent; tongue elliptical, posterior border notched, one-third not adherent to floor of mouth.

Skin on dorsum shagreen with scattered tubercles; dorsolateral folds absent; skin on lower flanks and belly areolate with scattered tubercles; skin on throat and chest smooth; discoidal fold absent; skin in upper cloacal region shagreen, wrinkled ventrally, with several tubercles below the cloacal sheath. Forearms slender; conical ulnar tubercles present along outer edge of forearm; all digits bearing pads and discs, broadly expanded and rounded but those of fingers II-IV clearly larger than that on thumb; fingers bearing narrow lateral fringes; relative lengths of fingers I <II <IV <III; subarticular tubercles single, well defined, round in ventral and lateral view; hyperdistal subarticular tubercles present in all fingers; several supernumerary tubercles at base of fingers present, distinct; palmar tubercle bifid, approximately 1.5 size of ovoid thenar tubercle (Fig. 6 ).

Hindlimbs slender; upper surfaces of hindlimbs smooth; posterior surfaces of thighs smooth, ventral surfaces of thighs slightly areolate; heel bearing low conical tubercles; inner surface of tarsus bearing small, low tubercles; toes with lateral fringes; webbing between toes absent; discs on toes expanded, elliptical, as large as those on fingers; all toes having pads surrounded by circumferential grooves; relative lengths of toes: I <II <III <V <IV; subarticular tubercles rounded, simple; hyperdistal subarticular tubercles present; plantar surface with supernumerary tubercles; inner metatarsal tubercle prominent, ovoid approximately five times of rounded outer metatarsal tubercle (Fig. 6 ).

Color of holotype in preservative. (Fig. 7 ) Background color pale brown with a dark brown interorbital bar and chevron marks in the scapular and sacrum region; a white mark extending from the posterior border of the upper eyelid to the scapular region; canthal and supratympanic stripe black, extending as a post-axial stripe on lower flanks; a dark brown Y-shaped mark at the tip of snout; dark brown transversal bars on dorsal surfaces of the limbs (three on the forearm, four to five on the thigh, five on the shank, and four on the foot); anal triangle dark brown; flanks and hidden surfaces of thighs pale brown; venter cream with white tubercles; scattered brown flecks on the neck, chest, and lips; ventral surfaces of hindlimbs and forelimbs creamy white with a brown suffusion.

Color of holotype in life. (Fig. 5 ) Dorsal surfaces of body and limbs olive green with black markings; canthal stripe and supratympanic fold black; flanks cream with one broad oblique bar; chest light green with small white spots; belly yellowish white; ventral surfaces of forelimbs and shanks faint green wash; ventral surfaces of thighs pale brown; iris bronze with black reticulations.

Variation.

In this section, variation refers to a preserved male QCAZ 39275 (Fig. 7 ) collected with the holotype in amplexus. The adult male (SVL = 16.3 mm) is smaller than the single known female (SVL = 20.4 mm). Measurements (in mm): tibia length 8.4; foot length 7.1; head length 6.4; head width 5.7; eye diameter 2.1; tympanum diameter 0.8; interorbital distance 2.1; upper eyelid width 1.7; internarial distance 1.7; eye-nostril distance 2.2; tympanum-eye distance 0.5. Male having vocal slits; nuptial pads absent.

Color in life (based on digital photographs; Fig. 5 ). Background coloration is olive brown with faint green dorsolaterally. Marks on dorsum and flanks are similar to the holotype, except for the interorbital bar that is interconnected with the chevron mark in the scapular region. Iris is reddish copper.

Distribution, natural history, and conservation status.

This species is only known from the type locality in Provincia de Pastaza, Ecuador at 430 m above sea level (Fig. 8 ). Natural region is Amazonian Tropical Rainforest (as defined by Ron et al. 2019). The forest is characterized by a high canopy (up to 30 m) with emergent trees that can reach 40 m. Annual precipitation is above 3000 mm and seasonality is low. The amplectant pair was on a leaf 0.4 m above the ground in primary forest near a stream at night.

We recommend assigning Pristimantis amaguanae to the Endangered Red List category according to the B2ab(iii) criteria (based on IUCN 2017 guidelines) because it is known from a single locality, its Area of Occupancy is less than 500 km2 and its only known locality is at a distance of 1.5 km from deforested areas (based on Google Earth satellite images dating from 2017). A road was built in the area ca. five years ago. Road building is the main predictor of forest destruction in the Ecuadorian Amazon ( Sierra 2013).

Etymology.

The specific name amaguanae is a noun in the genitive case and is a patronym for Tránsito Amaguaña, a leading female figure of the indigenous movement in Ecuador. In 1930 she helped to form the first indigenous organization in Ecuador and during all her life she fought for equality and justice for Ecuadorian poor people.

Figures

Figure 5. Live adult individuals A holotype of Pristimantis amaguanae sp. nov., adult female, QCAZ 39274 (SVL = 20.4 mm) B paratype of Pristimantis amaguanae sp. nov., adult male, QCAZ 39275 (SVL = 16.3 mm). Photographs by Jorge Valencia.

Figure 6. Ventral views of the left hand and foot of Pristimantis amaguanae sp. nov. Holotype (QCAZ 39274). Hyperdistal subarticular tubercles are pointed with arrows. Photographs by Julio C. Carrion.

Figure 7. Variation in preserved specimens of Pristimantis amaguanae sp. nov. A adult female, QCAZ 39274 (SVL = 20.4 mm) B adult male, QCAZ 39275 (SVL = 16.3 mm). Photographs by Maricela Rivera.

Figure 8. Known distribution of the three new species and type localities of P. paululus, P. petersi, and P. bromeliaceus. Localities are based on specimens deposited at Museo de Zoologia of Pontificia Universidad Catolica del Ecuador and from Lynch (1974), Lynch (1979), and Lynch and Duellman (1990).