AmphibiaWeb - Pristimantis amaguanae


(Translations may not be accurate.)

Pristimantis amaguanae Ron, Carrión, Caminer, Sagredo, Navarrete, Ortega, Varela, Maldonado & Terán, 2020
English name: Amaguaña’s Rain Frog; Spanish name: Cutín de Amaguaña
family: Strabomantidae
genus: Pristimantis
Species Description: Ron SR, J Carrión, MA Caminer, Y Sagredo, MJ Navarrete, JA Ortega, A Varela-Jaramillo, GA Maldonado-Castro, and C Terán. 2020. Three new species of frogs of the genus Pristimantis (Anura, Strabomantidae) with a redefinition of the P. lacrimosus species group. ZooKeys 993: 121–155.
Conservation Status (definitions)
IUCN Red List Status Account
National Status None
Regional Status None


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Pristimantis amaguanae is a slender-bodied frog described from two individuals, a female and male. The snout-vent length for the adult female specimen is 20.4 mm and 16.3 mm for adult male specimen. The head length is slightly more than width, which is wider than body. The snout is acuminate in the dorsal view and is protruding in the lateral profile. The loreal region is concave and the interorbital space is flat. It has no cranial crests, the eyes are large and protruding, and upper eyelid has numerous small tubercles. The tympanic membrane and annulus are distinct, rounded in shape with the supratympanic fold partially covering the upper and posterodorsal edges. The skin on the dorsum is shagreen with scattered tubercles, and there are no dorsolateral folds. The skin on belly and lower flanks is areolate with scattered tubercles, but the skin on the throat and chest are smooth. The discoidal fold is absent and the skin in the upper cloacal region is also shagreen. The stomach area is wrinkled and there are several tubercles below the cloacal sheath (Ron et al. 2020).

The forearms are slender with conical ulnar tubercles present along the outer edge of the forearm. All digits have pads and discs, which are broadly expanded and rounded. Fingers II - IV are clearly larger than the thumb, and the fingers have narrow lateral fringes. The relative lengths of the fingers are I < II < IV < III. The subarticular tubercles are singular, well-defined, and round in the ventral and lateral views. Hyperdistal subarticular tubercles are present in all fingers and there are several excess tubercles at the base of fingers (Ron et al. 2020).

The hind limbs are slender and the upper surfaces of hind limbs are smooth. The posterior surfaces of thighs are also smooth, and the ventral surfaces of thighs are slightly areolate. The heel has low conical tubercles, and the inner surface of the tarsus has small, low tubercles. The toes have lateral fringes and no webbing between them. The discs on toes are expanded, ellipse-shaped, and are as large as those on fingers. All the toes have pads surrounded by circumferential grooves. The relative lengths of the toes are I < II < III < V < IV. The subarticular tubercles are rounded and simple, and hyperdistal subarticular tubercles are present. The plantar surface has supernumerary tubercles, and the inner metatarsal tubercle is prominent, ovoid in shape, and approximately five times of a rounded outer metatarsal tubercle (Ron et al. 2020).

Pristimantis amaguanae resembles P. bromeliaceus and P. petersi but can be distinguished by the dark bands on the hind limbs of P. amaguanae. Additionally, P. amaguanae lacks a discoidal fold while P. bromeliaceus and P. petersi both have a discoidal fold. Pristimantis amaguanae is also smaller than P. bromeliaceus when fully matured; the single female and male P. amaguanae specimens have a snout-vent length of 20.4 mm and 16.3 mm, respectively, compared to P. bromeliaceus female snout-vent length ranges of 23.0 - 28.5 mm and male snout-vent length ranges of 16.7 - 22.8 mm. Pristimantis amaguanae has more tuberculate dorsal skin, no discoidal folds, and scattered enlarged light green warts in the venter, while P. paululus has discoidal folds and small white points. Pristimantis pseudoacuminatus has a truncate snout in profile and a lighter and more uniform color in preservative, while P. amaguanae has an acuminate snout in profile (Ron et al. 2020). A supertympanic fold in Pristimantis amaguanae differentiates it from P. achupalla (Ttito and Catenazzi 2021).

In preservative, the female P. amaguanae is pale brown with a dark brown interorbital bar and chevron marks in the scapular and sacral region. It has a white mark extending from the posterior border of the upper eyelid to the scapular region and a canthal-supratympanic black stripe that extends as a post-axial stripe on lower flanks. It has a dark brown Y-shaped mark at the tip of the snout, as well as dark brown transversal bars on dorsal surfaces of the limbs. It has a dark brown anal triangle, pale brown flanks and hidden surfaces of thighs, and cream venter with white tubercles. Scattered brown flecks are present on the neck, chest, and lips, and ventral surfaces of hind limbs. The creamy white forelimbs have a brown suffusion (Ron et al. 2020).

In life, the dorsal surfaces of the body and limbs are olive green with black markings. Both the canthal stripe and supratympanic fold are black and it has cream flanks with one broad oblique bar. The chest is light green with small white spots, while the belly is yellowish white. The ventral surfaces of the forelimb and shanks have a faint green wash, and the thighs are pale brown. The iris is bronze with black reticulations in the female (Ron et al. 2020).

The male and female differ in coloration. The male background coloration in life is olive brown with some faint green coloration dorsolaterally. Marks on the dorsum and flanks are like the female, except for the interorbital bar that is interconnected with the chevron mark in the scapular region. The iris is reddish copper (Ron et al. 2020).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Ecuador

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At the time of the species description, the species was only known from the type locality in Pastaza Province, Ecuador at 430 m above sea level. The natural region is the Amazonian Tropical Rainforest, and the forest has a high canopy of up to 30 m with emergent trees reaching 40 m. Annual precipitation is above 3000 mm and seasonality is low. Its area of occupancy is less than 500 km squared (Ron et al. 2020).

Life History, Abundance, Activity, and Special Behaviors
An amplectant pair of the species were found in October on a leaf 0.4 m above the ground in a primary forest near a stream at night (Ron et al. 2020).

Pristimantis amaguanae and P. achupalla share similar microhabitat and presumably ecological niche, but different geographical space (Tito and Catenazzi 2021).

Trends and Threats
The species authority, Ron et al. (2020), recommend P. amaguanae be added to the “Endangered” IUCN Red List category due to its single locality, small area of occupancy of less than 500 km squared, and a distance of 1.5 km from known deforested areas in 2017. A road was also built near the area the species inhabits, which may lead to future deforestation (Ron et al. 2020).

Possible reasons for amphibian decline

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


Maximum Likelihood analysis of 12S, 16S, and ND1 mtDNA and RAG-1 nDNA from the P. lacrimosus species group places P. amaguanae as sister to a clade composed of P. bromeliaceus and an undescribed species from Bombuscaro, Podocarpus National Park, Ecuador (Ron et al. 2020).

The species epithet, “amaguanae,” is a reference to Tránsito Amaguaña, who was 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 (Ron et al. 2020).


Ron, S. R., Carrión, J., Caminer, M. A., Sagredo, Y., Navarrete, M. J., Ortega, J. A., Varela-Jaramillo, A., Maldonado-Castro, G. A., and Terán, C. (2020). "Three new species of frogs of the genus Pristimantis (Anura, Strabomantidae) with a redefinition of the P. lacrimosus species group." ZooKeys 993, 121-155. [link]

Ttito, A. and Catenazzi, A. (2021). "Pristimantis achupalla sp. n., a new minute species of direct-developing frog (Amphibia, Anura, Strabomantidae) inhabiting bromeliads of the montane forest of the Amazonian Andes of Puno, Peru." PeerJ 9, e11878 [link]

Originally submitted by: Andrew Lee (2022-11-01)
Description by: Andrew Lee (updated 2022-11-01)
Distribution by: Andrew Lee (updated 2022-11-01)
Life history by: Andrew Lee (updated 2022-11-01)
Trends and threats by: Andrew Lee (updated 2022-11-01)
Comments by: Andrew Lee (updated 2022-11-01)

Edited by: Ann T. Chang (2022-11-01)

Species Account Citation: AmphibiaWeb 2022 Pristimantis amaguanae: English name: Amaguaña’s Rain Frog; Spanish name: Cutín de Amaguaña <> University of California, Berkeley, CA, USA. Accessed Jun 21, 2024.

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Citation: AmphibiaWeb. 2024. <> University of California, Berkeley, CA, USA. Accessed 21 Jun 2024.

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