Description
Pristimantis eriphus adults are moderately sized with a male snout-vent length between 18.1 – 25.2 mm and with two females specimens having snout-vent lengths of 25.8 and 29.0 mm. This frog has a head that is as wider than it is long and as wide or wider than its body. The snout is short and round in both the dorsal and lateral views. The lips are not flared in smaller individuals, but in adult females the lips flair slightly. The nostrils slightly protrude and are dorsolaterally directed. The canthal edge is generally sharp and straight in males whereas it is concave in females. The loreal area is concave. There is a single conical tubercle on the upper eyelid. The interorbital region has no cranial crests and is flat. The round tympanums are prominent, and about a third to a fifth the diameter of the eye. The tympanum is one tympanum length behind the eye, and has a short supratympanic fold above and behind the tympanum that conceals the tympanic annulus (Lynch and Duellman 1980).

The dorsal skin bears many small spinules that become sparser on flanks, making the skin look warty. It does not have dorsolateral folds. The ventral skin is coarsely areolate and has prominent discoidal folds that are anterior to the groin. It has subanal conical tubercles. The cloaca does not have a sheath (Lynch and Duellman 1980).

The forearms have conical to subconcial tubercles, which are partially connected in a ridge, on their ulna. The bifuid palmar tubercle is larger than the oval thenar tubercle. The palm also has many small supernumerary palmar tubercles. The fingers have thin lateral fringes. There is a lateral fold on the outer edge of the hand and the fourth finger. In smaller individuals there are basal subarticular tubercles on fingers I, III and IV. Finger II, and III have round, non-conical subarticular tubercles. Finger IV also has paired distal tubercles. In adult female individuals, the tubercles are single and the distal tubercle is wider than long. The fingers have broad discs on pads that are rounded on the tip. The pads are larger on fingers III and IV than on I and II (Lynch and Duellman 1980).

When the legs are flexed at 90 degrees from the body, the heels overlap. When the legs are extended along the body, the heel reaches the area between the eye and the nostril. The shank is more than half the length of the snout-vent length. The knee, heel, and the outer edge of the tarsus have small conical tubercles. The inner edge has zero to two tubercles and may instead have a thin tarsal ridge. The uncompressed inner metatarsal tubercle is 2 - 3 times longer than wide. The round, subconical outer metatarsal tubercle is a third to a sixth the size of the inner tubercle. The planter of the foot also has numerous supernumerary tubercles. The toes have thin lateral fringes on the inner and outer edges of the foot. Similarly to the fingers, the toes also have broad discs on pads with rounded tips. The largest pads are on the lateral toes (Lynch and Duellman 1980).

Pristimantis eriphus is differentiated from similar species by the dorsal skin bearing small spinules and by having a prominent tympanum, round snout, sharp canthal ridge, one tubercle on upper eyelid, not having a cranial crest, males with subgular vocal sac and vocal slits, the second finger being longer than the first, the finger pads being largest on the third and fourth fingers, broad discs, narrow lateral fringes on the fingers and toes, and the thighs barred with white and brown. More specifically, P. eriphus can be differentiated from P. calcaratus and P. crucifer by the former having a straight or weakly concave canthus rostralis and thighs with bold marks. Furthermore, P. eriphus has a shorter heel tubercle than P. calcaratus and P. crucifer has crenulated lateral fringes on their hands and feet. Large bars, instead of spots, on the thighs helps differentiate P. eriphus from the similar species, P. nigrogriseus and P. spinosus. Pristimantis spinosus also has a larger body size, cranial crests, upper eyelid tubercles, black posterior surfaces with white spots on the thigh and groin, and does not have vocal sacs in males that differentiate it from P. eriphus from with the latter being larger (Lynch and Duellman 1980).

In life, the dorsal surface is pale green with dark olive to brown markings and bars. The hidden surfaces and flanks are patterned with mottled cream and black coloration. The ventral surface is greenish white with dense of black marbling. The thighs are boldly barred with darker green or brown and white (Lynch and Duellman 1980). The iris is a bright reddish to copper color without reticulations (Ron et al. 2016). Preserved specimens are pale to medium brown with dark brown chevrons. There are stripes on the canthus and supratympanic region and there are indefinite bars on the lips. The flanks have a darker background than the dorsum but are white where the arms insert into the body and there are bars on the posterior end. The ventrum is also brown with darker marbling and spotting. The elbows have a white spot on the inner side and the forearms have diffuse brown bars. The thighs are bared with a light brown bar at the top and white and darker brown bars below. The hidden regions of the shank are dark brown with large white spots while the exposed regions have indistinct dark bars. The anal triangle is dark brown (Lynch and Duellman 1980).

There is variation of in the length of the snout with smaller individuals having relatively shorter snouts. The loreal region is also more concave and sloping in smaller individuals rather than gently sloping to the lips in larger individuals. These variations may be sex-related as the canthus rostralis varies between sexes, with males having straight canthus and females having concave ones (Lynch and Duellman 1980).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Colombia, Ecuador

View distribution map in BerkeleyMapper.

Pristimantis eriphus has been found in the upper cloud forests of the Rio Papallacta Valley on the eastern side of the Andes in Provincia Napo, Ecuador and Putumayo Department, Colombia at an elevation range between 2,160 – 2,750 meters. Specimens from the original description were found in partially cleared areas of cloud forests (Lynch and Duellman 1980), however, they have since been found in old growth cloud forest as well (Castro et al. 2010).

Life History, Abundance, Activity, and Special Behaviors
Pristimantis eriphus is a terrestrial, arboreal, and nocturnal species that is assumed to reproduce by direct development, however as of 2010, eggs have not been found in the wild (Castro et al. 2010).

Adults are more commonly found in high vegetation, above 100 cm, while juveniles are more commonly found on significantly lower perches than adults at night (Guayasamin and Funk 2009).

Their advertisement call sounds like “beep-ee-eep” (Lynch and Duellman 1980).

Trends and Threats
Although an IUCN Redlist assessment of P. eriphus found the species had a stable population, the species was given a threat status of “Vulnerable” because of habitat loss, fragmentation, and degradation due to logging and agricultural development. Some agricultural development included planting illegal crops (Castro et al. 2010).

The species is found in protected reserves in Ecuador. Specifically, they are found in the Reserva Ecológica Cayambe-Coca and the Reserva Ecológica Antisana (Castro et al. 2010).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing
Habitat fragmentation

Comments
The species authority is: Lynch, J. D., Duellman, W. E. (1980). “The Eleutherodactylus of the Amazonian Slopes of the Ecuadorian Andes (Anura : Leptodactylidae).” 69, Lawrence: University of Kansas, 28–30.

Baysian analysis of 12S and 16S mitochondrial DNA sequences indicate that P. eriphus is sister to a clade that includes P. supernatis and P. chloronotus (Rivera-Correa and Daza 2016).

The species epithet, “eriphus” is Greek for “a young goat” in reference to the frog’s goat-like call (Lynch and Duellman 1980).

Pristimantis eriphus is synonymous with Eleutherodactylus eriphus (Lynch and Duellman 1980, Castro et al. 2010)

References

Castro, F., Herrera, M., Ron, S.R., Coloma, L.A., Almeida, D., Lynch, J., Yánez-Muñoz, M. & Almendáriz, A. 2010. Pristimantis eriphus (errata version published in 2016). The IUCN Red List of Threatened Species 2010: e.T56584A86627465. http://dx.doi.org/10.2305/IUCN.UK.2010-2.RLTS.T56584A11487709.en. Downloaded on 13 September 2018.

Guayasamin, J., and Funk, W. (2009). ''The amphibian community at Yanayacu Biological Station, Ecuador, with a comparison of vertical microhabitat use among Pristimantis species and the description of a new species of the Pristimantis myersi group.'' Zootaxa, 2220, 41-66.

Lynch, J. D., Duellman W. E. (1980). ''The Eleutherodactylus of the Amazonian Slopes of the Ecuadorian Andes (Anura: Leptodactylidae).'' Miscellaneous Publications (University of Kansas. Museum of Natural History), 69, 1-86.

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.

Rivera-Correa, M., Daza, J.M. (2016). ''Molecular phylogenetics of the Pristimantis lacrimosus species group (Anura: Craugastoridae) with the description of a new species from Colombia.'' Acta Herpetologica , 11(1), 31-45.

Species Account Citation: AmphibiaWeb 2018 Pristimantis eriphus <https://amphibiaweb.org/species/2909> University of California, Berkeley, CA, USA. Accessed Dec 23, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 23 Dec 2024.

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