Pristimantis nankints, 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 nankints sp. nov. Figures 9 , 10 , 11 , 12

Material.

Holotype. QCAZ 71457 (field no. SC-PUCE 61965; Figs 9 - 11 ), adult female from Ecuador, Provincia Morona Santiago, Cantón Santiago de Méndez. Low part of the Cutucú mountain range in the vicinity of the house of Mr. Carlos Hurtado (2.78325°S, 78.15878°W), 1413 m above sea level. Collected by Diego Almeida, Diego Paucar, Darwin Núñez, Eloy Nusirquia and Ricardo Gavilanes on 01 January 2018. Paratypes (2). All specimens were collected in Ecuador, Provincia Morona Santiago. QCAZ 71458 (field no. SC-PUCE 61965), adult female collected with the holotype. QCAZ 69137 (field no. SC-PUCE 60012); adult male from Ecuador, Cantón Santiago, Puchimi (2.7780°S, 78.1682°W), 1364 m above sea level, collected by Diego Almeida, Darwin Núñez, Eloy Nusirquia and Jefferson Mora on 14 September 2017.

Suggested common name.

English: Nankints Rain Frog. Spanish: Cutín de Nankints .

Diagnosis.

A species of Pristimantis characterized by the following combination of characters: (1) skin on dorsum shagreen, skin on venter areolate with scattered warts, smooth on throat; discoidal fold absent; dorsolateral folds absent; (2) tympanic membrane and tympanic annulus present, upper edge of tympanic annulus covered by supratympanic fold; (3) snout short, protruding in lateral profile, acuminate in dorsal view, with rostral papilla; (4) upper eyelid without conical tubercles; cranial crests absent; (5) dentigerous processes of vomers present, prominent, oblique; (6) male having vocal slits, nuptial pads absent; (7) finger I shorter than finger II; discs of digits moderately expanded, rounded; (8) fingers bearing narrow lateral fringes; hyperdistal subarticular tubercles present; (9) ulnar and tarsal tubercles present, those on the tarsus are flattened and low, nearly inconspicuous; (10) heel without conical tubercles; inner tarsal fold present; (11) inner metatarsal tubercle prominent, elliptical, approximately 3 × as large as rounded, conical outer metatarsal tubercle; outer metatarsal tubercle small, rounded; supernumerary plantar tubercles inconspicuous (Fig. 10 ); (12) toes bearing narrow lateral fringes; toe webbing absent except for basal webbing between toes III and IV; toe V much longer than toe III (disc on toe III extends to the distal edge of the medial subarticular tubercle on toe IV, disc on toe V extends beyond the proximal edge of the distal subarticular tubercle on toe IV); hyperdistal subarticular tubercles present; toe discs smaller than those on fingers (Fig. 10 ); (13) in life, dorsum lime green to olive green with black to brown marks on dorsum; flanks green with black to brown longitudinal stripes on upper edge; chest and belly greenish cream, throat yellowish green; ventral surface of thighs lime green to pinkish green. Iris bronze with a broad dark brown horizontal band and black reticulations; (14) SVL in adult females 29.4 mm ± 2.2 (27.8-30.9, n = 2), SVL in one adult male 19.6 mm.

Comparisons with other species

(Fig. 12 ). In this section, coloration refers to live individuals unless otherwise noticed. Pristimantis nankints and P. romeroae have similar coloration in preservative. Pristimantis nankints differs by having small warts in the venter (numerous large warts in P. romeroae ) and by the size and shape of discs on fingers: expanded and truncate in P. romeroae vs. moderately expanded and rounded in P. nankints . Its green dorsal coloration resembles that of P. acuminatus , P. enigmaticus , P. limoncochensis , P. omeviridis , P. pseudoacuminatus , and P. tantanti . It differs from all of them by having a dark stripe bordering the upper edge of the flanks (dark stripe absent or if present, it is an oblique-lateral stripe starting behind the eye and ending near the ventral edge of the flank at midbody). It further differs from P. acuminatus , P. limoncochensis , and P. tantanti by having a prominent tympanum (tympanum absent in the three species; Duellman and Lehr 2009). Pristimantis enigmaticus and P. omeviridis differ by having a smaller tympanum (12-13% of head length [ Ortega-Andrade et al. 2015] vs. 20-25% in P. nankints ). Pristimantis pseudoacuminatus differs by having sparse tubercles and warts on the dorsum (tubercles and warts absent in P. nankints ; Shreve 1935).

Description of the holotype.

Adult female (QCAZ 71457; Figs 9 - 11 ). Measurements (in mm): SVL 30.9; tibia length 13.2; foot length 14.9; head length 11.4; head width 10.6; eye diameter 3.0; tympanum diameter 2.3; interorbital distance 3.8; upper eyelid width 2.8; internarial distance 2.3; eye-nostril distance 3.7; tympanum-eye distance#1.7. Body slender; head slightly wider than long, wider than body; snout short, protruding in lateral profile, acuminate in dorsal view, with rostral papilla; canthus rostralis distinct, slightly curved in dorsal view; loreal region slightly concave; interorbital space flat, no cranial crests; upper eyelid ca. 75% of interorbital distance; lacking tubercles, no interocular fold. Tympanic membrane and annulus present, rounded in shape, with supratympanic fold covering upper edge; horizontal diameter of tympanum ca. 75% of eye diameter, separated from eye by a distance of a complete tympanum length; choanae large, rounded, not concealed by palatal shelf of maxillary arc; dentigerous processes of vomers present, prominent, oblique, bearing 5 teeth, tongue cordiform.

Skin on dorsum shagreen; dorsolateral folds absent; skin on belly and posterior half of chest areolate with scattered warts; skin on anterior half of chest and throat smooth; discoidal fold absent; skin in upper cloacal region shagreen. Forearms slender with a row of four conical ulnar tubercles in outer edge of forearm; fingers large and slender, all with round discs; fingers bearing narrow lateral fringes; relative lengths of fingers I <II <IV <III; subarticular tubercles single, well defined, round in ventral view; hyperdistal subarticular tubercles present in all fingers; supernumerary palmar tubercles present, distinct; palmar tubercle bifid, 2 × size of ovoid thenar tubercle (Fig. 10 ).

Hindlimbs slender; tibia length ca. 50% of SVL; upper surfaces of hindlimbs smooth; foot length ca. 46 % of SVL, posterior surfaces of thighs smooth, ventral surfaces of thighs slightly areolate; knee and heel lacking tubercles; inner surface of tarsus lacking tubercles; toes bearing narrow lateral fringes; webbing between III and IV toes present at the base; discs on toes broadly expanded, rounded, relatively smaller than fingers; all toes having pads surrounded by circumferential grooves; relative lengths of toes: I <II <III <V <IV; subarticular tubercles rounded; hyperdistal subarticular tubercles present in all toes; plantar surface with inconspicuous supernumerary tubercles; inner metatarsal tubercle prominent, elliptical, approximately three times as large as rounded, conical outer metatarsal tubercle (Fig. 10 ).

Color of holotype in preservative. (Fig. 11 ) Background color pale gray with dark brown interorbital bar; light canthal and supratympanic black stripe continued by a long dorsolateral stripe bordering the upper flank; dorsal brown marks scattered on all dorsum except for two longitudinal bands adjacent to the dark dorsolateral stripe; color of venter, chest, and ventral surfaces of the limbs pale cream.

Color of holotype in life. (Fig. 9 ) Dorsal surfaces dark green with black spots and limbs yellowish green; canthal stripe and supratympanic fold black, continued by black dorsolateral stripe bordering the upper flank, the black stripe gradually fades in the upper flank and limits dorsally with a parallel light green band; chest and belly greenish cream, throat yellowish cream; ventral surfaces of forelimbs yellowish green and shanks faint green; ventral surfaces of thighs pinkish green; iris bronze with a broad dark brown horizontal band and black reticulations.

Variation.

(Fig. 11 ) In this section, coloration refers to preserved individuals. In the type series, the adult male has an SVL = 19.6 mm and the adult female 27.8 mm; (Table 3 ). The male has vocals slits and lacks nuptial pads. Dorsal coloration in preservative is light gray (e.g., QCAZ 71458) to yellowish cream (e.g., QCAZ 69137) with black dorsolateral bars and a black canthal stripe. Both paratypes have a lighter dorsolateral band bordered by the dark dorsolateral stripe and delimited medially by a faint black stripe (QCAZ 71458) or a row of black marks (QCAZ 69137). Both paratypes lack an interorbital bar but QCAZ 69137 has two dark marks instead. In QCAZ 69137 the flanks are yellowish cream; in QCAZ 71458 the flanks are gradually darker towards the black dorsolateral stripe. The tips of the fingers have the same color as the rest of the finger in QCAZ 69137 while in QCAZ 71458 they are darker.

Color in life (based on digital photographs of an adult male QCAZ 69137) (Fig. 9 ): dorsal surfaces are lime green; black-reddish canthal stripe is continued by black supratympanic fold and black dorsolateral stripe bordering the upper flank, the black stripe limits dorsally with a parallel light lime green band limited medially by two rows of black round marks; flanks, ventral and dorsal surfaces of limbs are green; belly and chest are greenish cream, throat greenish yellow; fingers, and toes greenish yellow; iris bronze.

Distribution, natural history, and conservation status.

Pristimantis nankints has been recorded at one locality in the eastern Andean slopes of Ecuador, Provincia Morona Santiago, Cordillera del Cutucú, 1364-1413 m above sea level (Fig. 8 ). Natural Region is Andean Eastern Montane Forest (according to Ron et al. 2019 classification) which is characterized by evergreen trees covered by mosses and abundant epiphytic plants.

Specimens were found at night along crystalline creek surrounded by secondary forest. The holotype was perching on a leaf 2 m above the ground, next to the stream; after capture, while in the plastic bag, the female deposited 22 eggs. The adult male was collected on secondary forest, on a terrestrial bromeliad. The female paratype was perching on a leaf 30 cm above the ground.

Pristimantis nankints distribution area is a mosaic of forest and deforested areas (based on Ministerio de Ambiente del Ecuador 2013). Its occurrence in secondary forest, near artificial open areas, indicates at least some level of resilience to anthropogenic habitat change. Nevertheless, there is not enough information to assess its risk of extinction. Therefore, we recommend its assignment to the Data Deficient Red List Category (DD) (based on IUCN 2017 guidelines).

Etymology.

The species name is a noun in apposition that refers to Nankints , a small hamlet in Cordillera del Cóndor, Ecuador, that used to be inhabited by Shuar native Americans. Its dwellers were violently evicted and Nankints was destroyed in 2016 to establish a mining camp. Large scale mining projects generate widespread deforestation and pollution in the Andes. The species name is a tribute to Ecuadorian people who have resisted mining activities in defense of the environment. Nankints is a shuar word that means spear.

Figures

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).

Figure 9. Live individuals of Pristimantis nankints A paratype, subadult male QCAZ 69137 (SVL = 19.6 mm) B holotype, adult female QCAZ 71457 (SVL = 30.9 mm). Photographs by Darwin Nunez (A), Gustavo Pazmino (B).

Figure 10. Ventral views of the left hand and foot of Pristimantis nankints sp. nov. Holotype (QCAZ 71457). Hyperdistal subarticular tubercles are pointed with arrows. Photographs by Julio C. Carrion.

Figure 11. Variation in preserved specimens of Pristimantis nankints sp. nov. From left to right, first and second rows: QCAZ 71457 (holotype, adult female, SVL = 30.9 mm), QCAZ 71458 (adult female, SVL = 27.8 mm), QCAZ 69137 (adult male, SVL = 19.6 mm). Photographs by Julio C. Carrion.

Figure 12. Live adult individuals of the clade of green Pristimantis within the P. lacrimosus complex and their closest relatives A Pristimantis acuminatus, QCAZ 53845 B P. limoncochensis, QCAZ 37277 C P. enigmaticus, QCAZ 66863 D P. omeviridis, QCAZ 55392 E P. sp., QCAZ 58956 F P. nankints sp. nov. QCAZ 69137 (SVL = 19.6 mm). Photographs by Santiago R. Ron (A-B), Gustavo Pazmino (C), Diego Quirola (D), Juan Carlos Sanchez (E) and Darwin Nunez (F).