Description

A relatively small frog, Pristimantis matildae has a snout vent length ranging from 20.8 - 23.3 mm in adult females and 19.9 - 21.2 mm in adult males. The head has a triangular shape with a pointed jaw that is longer than wide. The posteriorly oriented nostrils protrude slightly. In the dorsal view the canthus is weak, but in the profile it is angular. The lips are not flared. There is a postrictal tubercle that is round and large. The loreal region is slightly concave. The eye diameter is larger than the eye-nostril distance and there is one large tubercle and several smaller ones on the eyelid. There is no cranial crest, tympanic annulus/membrane, or supratympanic fold. The body tapers from the widest part of the head to the waist. The skin on the dorsum and flanks is finely tuberculated and has a mid-dorsal fold that starts at the snout and extends to the cloaca. There are no dorsolateral folds. The skin on ventral surfaces is aerolate. Two large oval tubercles can be found bordering the cloaca. The hands have a completely split outer palmar tubercle that is larger on the distal portion than the medial portion, an ovular inner/thenar tubercle that is larger than the medial outer palmar tubercle, and round supernumerary palmar tubercles. The fingers lack webbing, but have fringes and prominent subarticular tubercles, and end in round, grooved discs. The relative finger lengths are I < II < IV < III. No nuptial pads were observed. The legs are long. The heels have many small tubercles that extend onto the outer edge of the tarsus forming a small and inconspicuous row. The inner edge of the tarsus has a long fold. The inner metatarsal tubercle is oval while the outer metatarsal tubercle is rounded and elongated. The foot has small, round supernumerary tubercles. The toes have basal webbed, prominent lateral fringes, and prominent, round, subarticular tubercles. The toe tips expand slightly into truncated discs with circumferential grooves that are of similar size to the finger discs. The relative toe lengths are I < II < III < V < IV, with Toe V being much larger than Toe III (Székely et al. 2020).

DIAGNOSIS:

Pristimantis matildae shares many morphological similarities with other members of the Pristimantis orestes group, but can be differentiated from most by the lack of a tympanic annulus or membrane in P. matilda. This feature also distinguishes P. matildae from one of its closest relatives, P. muranunka. From the other two species, P. colodactylus and P. samaniegoi, that lack a tympanic annulus, P. matildae has much longer fingers and toes than P. colodactylus and P. matildae has a longer snout or head, relatively wider head, longer legs, and shorter fingers and toes than P. samaniegoi. Further morphological differences that distinguish P. colodactylus and P. matildae are that P. matildae has finely tuberculate skin, low middorsal folds, and more reddish eye coloration (Székely et al. 2020).

COLORATION:

In life, the dorsal surface of the body and limbs has a tan, dark brown, or gray background coloration. The body has either a dark brown hourglass shaped marking or an “X” shaped marking on their back and may have dorsolateral stripes. There are dark brown interorbital bars and canthal and supratympanic stripes. The eye coloration is red. The ventral surfaces of the body are pinkish gray, except for the throat, which like the ventral surface of the limbs, is light gray. In preservative, P. matildae has a dark gray dorsum with a brownish gray venter (Székely et al. 2020).

VARIATION:

There is some slight variation in patterning and coloration with some females exhibiting a yellow middorsal band, and other specimens having various sized yellowish-white spots on the dorsum and flanks (Székely et al. 2020).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Ecuador

View distribution map in BerkeleyMapper.

Pristimantis matildae have only been found in the Abra de Zamora and Cajanuma sections of Podocarpus National Park in the mountains of Ecuador. They have so far been limited to grasslands and thickets of the Andes mountains in elevations ranging from 2800 to 3360 meters (Székely et al. 2020).

Life History, Abundance, Activity, and Special Behaviors
Pristimantis matildae are only abundant in certain regions within Podocarpus National Park in Ecuador. They can be found in or around both terrestrial and arboreal bromeliads during the day and night. When threatened, they retreat rapidly to the water contained in the bromeliad (Székely et al. 2020).

They feed on small insects such as termites (Székely et al. 2020).

Trends and Threats
Pristimantis matildae is only found in two localities that are near each other, covering an area less than 50 km². At the time of their description, the authors recommended a threat status of “Near Threatened” because although they are relatively abundant at those sites and their habitat is not currently threatened, the potential habitat loss to their small range would have a large impact (Székely et al. 2020).

Possible reasons for amphibian decline

General habitat alteration and loss

Comments

PHYLOGENETIC RELATIONSHIPS:

Based on Bayesian inference and Maximum likelihood analysis of the 12S, 16S, and RAG-1 genes, P. matildae is most directly related to the clade composed of P. colodactylus, P. muranunka and an undescribed species (Székely et al. 2020).

ETYMOLOGY:

The species epithet, “matildae” is in honor of Matilde Hidalgo Navarro. She was the first woman to obtain a medical degree and vote in Ecuador, as well as a proponent for the advancement of women in Ecuadorian society and biodiversity conservation efforts (Székely et al. 2020).

References

Székely P., Eguiguren J. S., Ordóñez-Delgado L., Armijos-Ojeda D., Székely D. (2020). “Fifty years after: A taxonomic revision of the amphibian species from the Ecuadorian biodiversity hotspot Abra de Zamora, with description of two new Pristimantis species.” PLOS ONE, 15(9), e0238306. [link]

Species Account Citation: AmphibiaWeb 2023 Pristimantis matildae: Matilde’s Rain Frog <https://amphibiaweb.org/species/9257> University of California, Berkeley, CA, USA. Accessed May 3, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 3 May 2024.

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