Pristimantis yanezi, Navarrete, Maria J., Venegas, Pablo J. & Ron, Santiago R., 2016

Navarrete, Maria J., Venegas, Pablo J. & Ron, Santiago R., 2016, Two new species of frogs of the genus Pristimantis from Llanganates National Park in Ecuador with comments on the regional diversity of Ecuadorian Pristimantis (Anura, Craugastoridae), ZooKeys 593, pp. 139-162 : 141-148

Taxon classification Animalia Anura Craugastoridae

Pristimantis yanezi sp. n.

Common name.

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

Holotype

QCAZ 46259 (field no. SC-PUCE 29819; Figs 2 A–B, 3 A–B, 4 A–B), adult male from Ecuador, Provincia Napo, Cantón Tena, on the road from Salcedo to Tena (1.0090°S, 78.1883°W), 2095 m, collected by Elicio E. Tapia and Fernando Núñez on 17 November 2009.

Paratopotypes

(2 specimens). QCAZ 46257 adult female, 46258 adult male, collected with the holotype.

Paratype

(1 specimen). QCAZ 45964 adult male from Ecuador, Provincia Pastaza, Cantón Santa Clara, Communal Reserve Ankaku (1.2792° S, 78.0779° W), 2280 m, collected by Elicio E. Tapia on 24 October 2009.

Diagnosis.

The new species is assigned to the genus Pristimantis . Although morphological synapomorphies are unknown for Pristimantis , the new species has the characteristic morphology of most Pristimantis including T-shaped terminal phalanges, toes without membranes, and Toe V longer than Toe III. Pristimantis yanezi is characterized by the following combination of characters: (1) Skin on dorsum smooth in the anterior half and shagreen or tuberculate in the posterior half, skin on venter areolate to weakly areolate; discoidal fold absent; dorsolateral folds absent; (2) tympanic membrane and tympanic annulus present, its upper and posterior margin covered by supratympanic fold; (3) snout short, rounded in dorsal and lateral view; (4) upper eyelid with one distinct conical tubercle surrounded by some low indistinct rounded tubercles; EW 92% of IOD; cranial crests absent; (5) dentigerous processes of vomers prominent, oblique, moderately separated, posteromedial to choanae; (6) vocals slits and nuptial pads absent; (7) Finger I shorter than Finger II; discs of digits expanded, truncate; (8) fingers without lateral fringes; (9) ulnar and carpal tubercles present, low and rounded; (10) heel bearing one low conical tubercle surrounded or not by few lower rounded tubercles; inner tarsal fold present, short; (11) inner metatarsal tubercle elliptical, prominent, 3X as large as outer metatarsal tubercle; outer metatarsal tubercle small, ovoid; low, numerous distinct supernumerary plantar tubercles; (12) toes without lateral fringes; basal toe webbing absent; Toe V slightly longer than Toe III (disc on Toe III reaches the middle of the penultimate subarticular tubercle on Toe IV, disc on Toe V does not reach the subarticular tubercle on Toe IV); toe discs about as large as those on fingers; (13) in life, dorsum yellowish brown to dark brown with scattered pale brown or orange blotches and black flecks, bearing a faint middorsal hourglass-shaped band; head bearing a dark brown interorbital bar and sides of head brown with darker vertical labial bars; flanks dark brown or olive brown with distinct dark brown to black flecks and diffuse dark brown diagonal stripes; groins cream or brownish cream; venter light cream to dirty cream with dark brown flecks and with or without dark brown mottling on the throat; iris reddish coppery; (14) SVL in adult female 36.9 mm (n = 1), in adult males 23.7-29.8 mm (n = 3).

Comparison with other species.

In this section, coloration refers to live individuals unless otherwise noted. Pristimantis yanezi is similar to congeneric species characterized by a spiny appearance (i.e. presence of conical tubercles on dorsum, eyelids, heels and outer edge of tarsus). It differs from these species and from other Pristimantis by the combination of the following characters: iris reddish coopery, dorsum yellowish brown to brown bearing scattered pale brown to orange blotches; skin on flanks shagreen with small scattered tubercles and bearing distinctive brown to black flecks; upper eyelid, heel and outer edge of tarsus with small conical tubercles; venter and throat cream to dirty cream covered by brown flecks or brown mottling; groins cream or brownish cream; posterior surfaces of thighs and concealed surfaces of shanks brown or olive brown. Adult males of Pristimantis yanezi can be distinguished from Pristimantis chloronotus ( Lynch 1969), Pristimantis colonensis ( Mueses-Cisneros 2007), Pristimantis crucifer ( Boulenger 1899), Pristimantis eriphus ( Lynch and Duellman 1980), Pristimantis galdi ( Jiménez de la Espada 1870), Pristimantis inusitatus ( Lynch and Duellman 1980), Pristimantis llanganati sp. n., Pristimantis mutabilis Guayasamin, Krynak, Krynak, Culebras, and Hutter 2015, Pristimantis rufoviridis Valencia, Yánez-Muñoz, Betancourt-Yépez, Terán-Valdez, and Guayasamin 2011, Pristimantis roni Yánez-Muñoz, Bejarano-Muñoz, Brito M., and Batallas 2014, and Pristimantis verecundus ( Lynch and Burrowes 1990) in lacking vocal slits. Pristimantis bellae Reyes-Puig and Yánez-Muñoz 2012, Pristimantis colonensis , Pristimantis inusitatus , Pristimantis roni , and Pristimantis rufoviridis also differ from Pristimantis yanezi by having a prominent conical tubercle on the eyelids and heels (conical tubercle is small in Pristimantis yanezi ; Fig. 1). Furthermore, Pristimantis bellae has the groins, anterior and posterior surfaces of thighs, and concealed surfaces of shanks black with white spots or blotches (groins are cream or brownish cream and posterior surfaces of thighs and concealed surfaces of shanks are brown or olive brown with scattered faint cream flecks in Pristimantis yanezi ). Pristimantis colonensis further differs from Pristimantis yanezi in having narrow white diagonal stripes on flanks (flanks with faint dark brown diagonal stripes in Pristimantis yanezi ; Fig. 1). In dorsal view, Pristimantis inusitatus has the snout subacuminate with a pointed tip, while in Pristimantis galdi and Pristimantis rufoviridis the snout is acuminate (snout is rounded in Pristimantis yanezi ). Pristimantis roni has lateral fringes on fingers and toes (absent in Pristimantis yanezi ). Pristimantis chloronotus , Pristimantis eriphus , and Pristimantis llanganati sp. n. can be easily distinguished from Pristimantis yanezi by having flanks with clear and dark diagonal bars (flanks without bars in Pristimantis yanezi ). Additionally, Pristimantis chloronotus has a pair of sinuous paravertebral folds (absent in Pristimantis yanezi ). Furthermore, Pristimantis eriphus has the dorsum covered by many minute conical tubercles (dorsum smooth to shagreen in Pristimantis yanezi ). Pristimantis incanus ( Lynch and Duellman 1980) can be easily distinguished from Pristimantis yanezi by having groins yellow to light green or red (reddish brown in ethanol) with contrasting light or dark marks (groins are cream to tan cream without contrasting marks in Pristimantis yanezi ). Pristimantis crucifer and Pristimantis katoptroides (Flores, 1988) differ from Pristimantis yanezi by having blue groins (cream or brownish cream in the new species). Both species also differ in iris coloration: red in Pristimantis crucifer and cream with black reticulations in Pristimantis katoptroides (iris reddish coopery in Pristimantis yanezi ). Finally, Pristimantis yanezi differs from Pristimantis mutabilis and Pristimantis verecundus in lacking dorsolateral folds and red coloration in the groins.

Description of the holotype.

Adult male. Measurements (in mm): SVL 29.8; tibia length 17.0; foot length 14.8; head length 8.6; head width 11.5; eye diameter 3.7; tympanum diameter 1.1; interorbital distance 3.4; upper eyelid width 3.1; internarial distance 2.7; eye–nostril distance 3.3; tympanum–eye distance 1.5. Head wider than long, wide as body; head width 39% of SVL; head length 29% of SVL; snout rounded in dorsal view and in profile; eye–nostril distance 87% of eye diameter; nostrils narrow, higher than long, directed dorsolaterally; canthus rostralis distinct in lateral view, curved in dorsal view; loreal region concave; lips rounded; upper eyelid bearing one small but distinct conical tubercle surrounded by few indistinct smaller tubercles; upper eyelid width 92% of IOD; tympanic annulus distinct, with upper and posterior margins covered by supratympanic fold; tympanic membrane present, distinct; tympanum diameter 30% of eye diameter, tympanum–eye distance 134% of tympanum diameter; one enlarged conical postrictal tubercle surrounded by indistinct low tubercles. Choanae large, semicircular, not concealed by palatal shelf of maxilla; dentigerous processes of vomers prominent, oblique, moderately separated, positioned posteromedial to choanae; each vomer bearing several indistinct teeth; vocal slits absent; tongue two times wider than long, notched behind, free posteriorly along one third of its length.

Skin on dorsum smooth in the anterior half and shagreen in the posterior half; dorsolateral folds absent; skin on flanks with scattered tubercles; skin on throat, chest and belly weakly areolate, ventral surfaces of thighs areolate; discoidal fold absent; cloacal sheath short; skin in upper cloacal region shagreen, wrinkled ventrally, with several tubercles below the cloacal sheath. Ulnar tubercles present, indistinct; nuptial pads absent; palmar tubercles low, outer palmar tubercle bifid, approximately twice size of ovoid thenar tubercle; subarticular tubercles low, well defined, round in ventral and lateral view; supernumerary tubercles at base of fingers present, distinct; fingers lacking lateral fringes; Finger I shorter than Finger II; disc on Finger I rounded and on Finger II expanded, disc on Finger III and Finger IV broadly expanded and truncate; pads on fingers well defined, surrounded by circumferential grooves on all fingers (Fig. 2).

Hindlimbs slender, tibia length 57% of SVL; foot length 50% of SVL; upper surfaces of hindlimbs smooth; posterior surfaces of thighs smooth, ventral surfaces of thighs areolate; heel bearing one low conical tubercle surrounded by some low rounded tubercles; outer surface of tarsus bearing low but distinct sub-conical tubercles; short inner tarsal fold present; inner metatarsal tubercle prominent, elliptical, rounded, much bigger than oval, ill-defined outer metatarsal tubercle; plantar surface with some supernumerary tubercles; subarticular tubercles well defined, round in ventral and lateral view; toes lacking lateral fringes; webbing between toes absent; discs nearly as large as those on fingers, most prominent on Toe IV and V; discs on toes expanded, elliptical; all Toes having pads surrounded by circumferential grooves, less distinct on Toe I; relative lengths of toes: 1 <2 <3 <5 <4 (Fig. 2); Toe V longer than Toe III (disc on Toe III reaches the middle of the penultimate subarticular tubercle on Toe IV, disc on Toe V extends to proximal edge of distal subarticular tubercle on Toe IV).

Color of holotype in life (based on digital photographs) (Fig. 3): dorsal surfaces of body, limbs, fingers and toes olive brown bearing a faint mid-dorsal hourglass-shaped band paler than the rest of dorsum, with brown flecks in the posterior half; top of the head, anterior to dark brown interorbital stripe, paler than the rest of head and dorsum; brown canthal stripe; two brown labial bars below orbit; flanks with faint brown diagonal stripes and scattered dark brown flecks, groins with a pale brown blotch; dorsal surfaces of forelimbs bearing dark brown flecks and diffuse brown bands; dorsal surfaces of thighs with faint brown bars and posterior surfaces of thighs olive brown; shanks, tarsus and feet bearing scattered brown flecks. Ventral areas of body, limbs, palms and soles yellowish cream with faint cream mottling on the throat and belly, scattered dark brown flecks on chest and belly, palms and soles. Iris reddish coppery.

Color of holotype in ethanol 70% (Fig. 4): dorsal surfaces of body, limbs, fingers and toes pale grayish brown, hourglass-shaped middorsal band is paler than the rest of dorsum, head is dusty brown darker than dorsum, the interorbital stripe is bright cream and the occipital region dark brown; sides of head dusty brown with dark brown canthal stripe and labial bars; flanks paler than dorsum with diffuse brown diagonal stripes and scattered brown flecks, groins with a pale cream blotch; dorsal surfaces of forelimbs bearing dark brown flecks, especially on fingers, and diffuse brown bands; dorsal surfaces of thighs with indistinct faint brown bars and posterior surfaces of thighs creamy brown with faint pale flecks; shanks, tarsus, and feet darker than thighs bearing scattered brown flecks and faint brown bands. Ventral areas of body, limbs, palms, and soles dirty cream with faint cream mottling on the throat and belly, scattered dark brown flecks on chest, belly, thighs, palms, and soles.

Variation.

In this section, coloration refers to preserved individuals. In the type series, adult males (23.7-29.8 mm) are smaller than the single known female (SVL = 36.9 mm). See Table 1 for measurements and proportions of the type specimens. Males lack vocals slits and nuptial pads. The middorsal hourglass-shaped band can be ill defined (QCAZ 46258) or absent (QCAZ 45964) (Fig. 5). Background coloration varies from brown or dark brown to olive yellow. Marks on dorsum and flanks are similar in all paratypes, except for the interorbital bar, that can be broad (QCAZ 46257) or narrow (QCAZ 45964) and brown (QCAZ 46257) or cream (QCAZ 46258). In life and preservative (Fig, 3; Fig. 5, respectively), the top of head anterior to the orbits can be darker than the rest of dorsum, except in QCAZ 46258 whose head and dorsum are uniform dark brown.

Coloration in life (based on digital photographs of adult female QCAZ 46257 and of male QCAZ 45964) (Fig. 1; Fig. 3): dorsum dark olive yellow to brown with scattered dark brown flecks, two dark brown (QCAZ 46257) or pale brown (QCAZ 45964) scapular spots, dorsum bearing an hourglass-shaped mark in the mid-dorsum (less defined in QCAZ 45964); head with dark brown interorbital bar; sides of head brown with dark brown canthal stripe and brown labial bars, flanks dark brown with black flecks, groins with creamy yellow blotches; dorsal surface of forelimbs dirty light brown with dark brown marks and dark brown flecks on fingers; dorsal surfaces of thighs brown with faint (QCAZ 45964) or conspicuous (QCAZ 46257) brown diagonal bars; shanks light brown with dark brown diagonal stripes, tarsus and feet dirty brown with dark brown bars (QCAZ 46257) or dark brown blotches (QCAZ 45964). Throat brownish cream, chest and belly cream with scattered dark brown flecks; ventral surfaces of thighs, shanks, and tarsus brownish cream; palmar and plantar surfaces brown. Iris reddish copper. Sexual dimorphism in morphology could not be evaluated due to the limited sample size (n = 4; one female and three males).

Distribution, natural history, and conservation status.

Pristimantis yanezi is known from two localities (elevation range is 2095-2280 m) from Provincia del Tungurahua and Provincia del Pastaza, Parque Nacional Llanganates. Airline distance between localities is 32 km. Ecosystem type is Evergreen Montane Forest of the Eastern Andean Cordillera (as defined by Ministerio de Ambiente del Ecuador 2013) or Eastern Montane Forest (as defined by Ron et al. 2016).

The holotype and the paratopotypes were collected at night, on vegetation on recently logged forest. The paratype was collected at night, on a branch (1 cm diameter) 2 m above the ground. A deforestation map by Ministerio de Ambiente (2013) shows continuous forest at the known localities. Because we lack population data and most of the Llanganates region lacks amphibian inventories, we assign Pristimantis yanezi to the Data Deficient Red List category (based on IUCN 2001 guidelines).

Etymology.

The specific name yanezi is a noun in the genitive case and is a patronym for Mario Yánez who provided useful insights for the description of the new species. Moreover, during his career, Mario Yánez has contributed significantly to the study of Ecuadorian amphibians, especially those of the genus Pristimantis . He is director of Museo Ecuatoriano de Ciencias Naturales (MECN).

Remarks.

Most species groups within Pristimantis have been defined exclusively on morphological grounds (e.g., Lynch and Duellman 1997). With few exceptions, those groups resulted artificial (i.e., non-monophyletic) once phylogenies based on genetic characters were used to evaluate them (e.g., Pinto-Sanchez et al. 2012). Because morphological characters in Pristimantis are unreliable to assess phylogenetic affinities, we refrain from assigning Pristimantis yanezi to a species group.