Description
Pristimanti yanezi is a small frog. The snout-vent lengths of three males range from 23.7 - 29.8 mm, and the only known female specimen has a snout-vent length of 36.9 mm. The head is wider than it is long, and it is approximately one-third of the snout-vent length. The snout is short and rounded in in the dorsal and lateral views. The nostrils are narrow. The canthus rostralis is curved when viewed dorsally, and the loreal region is concave. The lips are rounded. The upper eyelid bares one noticeable conical tubercle surrounded by small, indistinct rounded tubercles. The margins of the tympanic membrane and annulus are hidden dorsally and posteriorly by a discoidal fold. The choanae is large, semicircular, and visible. There are no vocal slits. The anterior half of the dorsal skin is smooth, changing to shagreen or tuberculate posteriorly. The discoidal fold and dorsolateral folds are absent. The ventral skin is areolate or weakly areolate. The hind limbs are slender and the skin is smooth. The terminal phalanges are T-shaped. The discs of digits are expanded yet truncate, Finger II is longer than Finger I, and all fingers and toes lack lateral fringes. The discs of all digits are expanded and truncate. Low, rounded tubercles are visible on the ulna and carpals and a low conical tubercle is present on the heel. There is a short, inner tarsal fold, a large, elliptical inner metatarsal tubercle three times the size of the ovoid outer metatarsal tubercle and many small plantar tubercles. Discs on toes are comparable in size to those on the fingers. There are no membranes between the toes. Toe V is longer than Toe III, which is characteristic of the Pristimanti genus. Pads on the fingers are well defined and surrounded by grooves (Navarrete et al. 2016).

Pristimantis yanezi can be distinguished from all other congeners within its distribution range by the combination of a relatively smooth dorsum, small tubercles on the eyelid and heel, coppery red iris, primarily brown dorsal coloration, an hourglass-shaped middorsal band, discreet dark (dark brown or black) flecks on the flanks, a cream colored venter with brown flecks or mottling, a cream or brownish cream groin and lack of dorsolateral fold or vocal slits. Male Pristimantis yanezi individuals lack vocal slits, which are present in P. chloronotus, P. colonensis, P. crucifer, P. eriphus, P. galdi, P. inusitatus, P. llanganati, P. mutabilis, P. rufoviridis, P. roni, and P. verecundus. The conical tubercle on P. yanezi is small, but P. bellae, P. colonensis, P. inusitatus, P. roni, and P. rufoviridis have noticeable conical tubercles on their heels and eyelids. Many Pristimantis species have pointed snouts, but P. yanezi has a rounded snout. Pristimantis yanezi can be differentiated from many species by their cream groins. Pristimantis bellae has black groins and thighs with a few white spots. Pristimantis incanus has yellow, light green, or red groins with contrasting light or dark marks. Pristimnatis crucifer and P. katoptroides have blue groins. Additionally, P. yanezi has faint brown stripes on its flanks, but P. colonensis has white stripes on its flanks. Pristimantis yanezi has no bars on its flanks, but dark diagonal bars are present on the flanks of P. chloronotus, P. eriphus, and P. llanganati (Navarrete et al. 2016).

According to the original description, the dorsal color in life can be yellowish brown to dark brown or dark olive yellow. However, some specimens collected more recently by the Zoology Museum at the Pontifical Catholic University of Ecuador (QCAZ) exhibit a light yellow-green dorsal color (Páez-Rosales 2018). This demonstrates the pronounced intraspecific morphological variation commonly observed in Pristimantis, often making species difficult to diagnose based on superficial characteristics alone. All specimens have scattered pale brown to orange blotches and black flecks on the dorsum. An hourglass-shaped band spans the middorsum and is lighter than the flanking regions; this marking is less distinct in some individuals. Two dark or pale brown scapular spots are present in most, but not all individuals. The species presents a dark brown interorbital bar that may be wide or narrow. The sides of the head may be brown, olive, or yellow-green, with dark labial bars and canthal stripe. The flanks are darker than the dorsum and bear dark brown or black flecks. The groin is cream to creamy yellow or creamy brown. Dorsal surfaces of limbs, fingers and toes olive brown, light brown, dirty brown, or pale yellow with dark flecks and blotches. The thighs and shanks bear distinct or faint brown bars. The ventral surfaces of the limbs, hands and feet can be cream to creamy brown to brown with dark speckling. The belly and throat is light cream to dirty cream with dark brown flecks. Dark mottling may be variably present on the throat. (Páez-Rosales 2018, Navarrete et al. 2016).

Coloration and markings in specimens preserved in 70% ethanol are generally similar to those in life. Preserved individuals are paler overall, with dark browns fading to lighter/dusty brown and lighter browns or olive brown fading to pale grayish brown, light gray, pale olive yellow, or dirty cream. The hourglass-shaped middorsal band which is a key diagnostic feature in life may be inconspicuous or absent in preserved specimens. Additionally, individuals may have a poorly-defined or absent middorsal band. The background color of P. yanezi can range anywhere from dark brown to olive yellow. Most markings on dorsum and limbs are similar, except for the varying widths and colors of the interorbital bar. While the top of the head is darker than the dorsum in most individuals, some may have uniform coloration on both body parts. It’s likely that there is sexual dimorphism in this species; all of the collected male individuals were smaller than the single female collected. Males also lack vocal slits and nuptial pads, but these are present in females (Navarrete et al. 2016).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Ecuador

View distribution map in BerkeleyMapper.

Pristimantis yanezi is endemic to eastern montane forests of Ecuador between 2095 and 2280 m in elevation. It is known from two localities in the provinces of Tungurahua and Pastaza within Llanganates National Park. Specimens were collected at night, and they were perched on vegetation in a recently-logged forest (Navarrete et al. 2016).

Life History, Abundance, Activity, and Special Behaviors
Like other Pristimantis frogs, P. yanezi has terrestrial eggs, meaning they’re laid on land (Navarrete et al. 2016).

Trends and Threats
Due to the lack of population data and sampling within its native range at the time of the species description, Navarrete et al. (2016) recommend that P. yanezi be assigned a "Data Deficient" status under IUCN criteria.

Comments

Pristimantis yanezi is morphologically identifiable from other Pristimantis species. However, phylogenetic analyses has not yet been conducted on this species (Navarette et al. 2016).

The species epithet “yanezi” is a patronym for Mario Yánez, an Ecuadorian herpetologist who has contributed greatly to the study of Pristimantis (Navarrete et al. 2016).

References

Navarrete, M.J., Venegas, P.J., Ron S.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, 139-162. [link]

Species Account Citation: AmphibiaWeb 2021 Pristimantis yanezi: Yánez Rain Frog. Spanish: Cutín de Yánez <https://amphibiaweb.org/species/8479> University of California, Berkeley, CA, USA. Accessed Nov 21, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 21 Nov 2024.

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