Description
Pristimantis aureoventris is a small frog with male snout-vent length ranges from 19.6 - 22.7 mm and females lengths from 24 - 29 mm. The snout is slightly oval when viewing dorsally but is rounded and slightly sloping in profile. The canthus rostralis ranges from straight to slightly curved, and the upper eyelid may be smooth or slightly grainy and often has 1 - 2 enlarged tubercles per eyelid. A tympanum is visible but reduced in size to less than half the eye size. Males lack vocal slits, however they do possess a vocal sac. Dorsal skin is slightly rough or granular and highly variable in coloration and pattern. The ventral skin is areolate. Tubercles are present on the outer forearm, however, they are shallow and inconspicuous. Finger I is shorter than finger II and this species also possesses wide lateral fringes on their fingers. Tarsal and calcar tubercles on the feet are present, but shallow and inconspicuous. The circular outer metatarsal is half to one-fourth the size of the oval inner metatarsal tubercle. Their toes also possess broad lateral fringes and there is webbing between toes IV and V. Lastly, toe V is longer than toe III (Kok et al. 2011).

Diagnosis:

This species can be distinguished from 21 other species in the genus Pristimantis that are found in the Pantepui region by the following characteristics: finger I is shorter than finger II, presence of a visible tympanum, lack of vocal slits, presence of fringes on fingers and toes, presence of nuptial pads in males, and smaller adult female size. This species is additionally differentiated from the closest geographically located species in this genus, P. yuruaniensis, because it possesses much more polymorphism in color and pattern and its internal organs are significantly less visible from its ventral side (Kok et al. 2011).

Coloration:

In life, dorsal skin varies from golden brown to dark brown. A W-shaped mark may appear on the shoulder blade. The snout may be lighter in color than the body but contains dark markings. Several specimens had a postocular stripe dark that runs along the tympanum. Some specimens possess two light brown stripes running down the back with dark brown spots and outlined in a thin eggshell-colored line. Similar bands that range from light grayish brown to dark brown were present on some specimens, but not all. Often the flanks are characterized by light brown and dark brown bands with similar but faint cross bands on the legs. The ventrum is golden yellow in color with reddish-brown or dark brown mottling. The skin is slightly translucent to opaque, but the internal organs are barely visible. The arms and legs are reddish-orangish brown and the groin is black or brown. Individuals may also possess a red-orange flash mark in the groin area directly in front of the hind legs and the groin may possess golden spots. Preservation led to the darkening of pigment and fading of patterns in all specimens. The orange-flash mark found on a male’s flank turned white after preservation (Kok et al. 2011).

Variation:

Variation in coloration and pattern make up the majority of intraspecific variation. Sexual dimorphism is limited; females are larger than males and males posess two nuptial pads that are whitish in color and lack spines (Kok et al. 2011).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Brazil, Guyana, Venezuela

View distribution map in BerkeleyMapper.

Pristimantis aureoventris is found in northern South America in the Pantepui mountainous regions, locally known as tepuis. They were originally found only in two separate but closely located summits of Mount Roraima in Guyana, and Wei Assipu Tepui at the border of Guyana and Brazil (Kok et al. 2011). However, later surveys found this species at another neighboring tepui named the Kukenán Tepui and located in Venezuela (Jablonski et al. 2017). Specimens were found at elevations ranging from 2210 - 2305 m. The Pantepui mountains are made of sandstone and are flat at their peaks. Vegetation in the Wei Assupu Tepui is mainly populated by shrubs and bromeliads but littered with regions of dwarf forests and quaking bog. In contrast, Mount Roraima is rockier and vegetation is sparse but similar to that found on Wei Assipu Tepui (Kok et al. 2011).

Life History, Abundance, Activity, and Special Behaviors
The species is presumed to be nocturnal as this was when most specimens were captured. The species is abundant, although it was difficult for researchers to locate and capture individuals (Kok et al. 2011). It is a terrestrial species (IUCN 2021); most specimens were found on the lower leaves of Orectanthe sceptrum and Broncchinia tatei. However, two females were found at night on an exposed rock and on the branch of a tree (Kok et al. 2011).

Males call at night from concealed locations in the lower leaves of Orectanthe sceptrum. Calls consist of a single note with a duration of 0.017 - 0.023 s and a rate of approximately 18 calls per minute. The fundamental frequency of the call ranges from 2180 - 2430 Hz and the inter-call interval is 2.73 - 3.51 s. The call has three harmonics, with the third containing more sound energy than the second. To the human ear, the call resembles a droplet falling into water (Kok et al. 2011).

Clutches of 4 - 5 eggs were found in early November in the crevices of dead marsh pitcher plants, Heliamphora nutans. They ranged in size from 5.25 - 6.1 mm and were yellow in color with a translucent membrane (Kok et al. 2011).

Similar to other frogs in this genus, this species exhibits direct development (Kok et al. 2011).

Trends and Threats
This species’ IUCN Red List status is “Endangered”. While there is not enough research to determine population trends, anthropomorphic climate change is affecting the tepuis where this species resides. Increases in fires as a result of decreased rainfall and human actions in Venezuela has resulted in decline to the vegetation of this habitat. This species occurs in at least one protected area; the Kukenán Tepui is within the Canaima National Park (IUCN 2021).

Possible reasons for amphibian decline

Climate change, increased UVB or increased sensitivity to it, etc.

Comments

Phylogenetic Relationships:

Pristimantis aureoventris was assigned to the genus based on preliminary molecular phylogenetic information. However, the phylogenies were not published with the species description (Kok et al. 2011). The closest geographical Pristimantis species, P. yuruaniensis, which is also found on the Kukenán Tepui, was identified as the closest related species to P. aureoventris (Jablonski et al. 2017).

Etymology:

The species epithet, “aureoventris” is a Latin reference to their golden ventral face with “aureus” meaning “golden” and “ventris” meaning “venter” (Kok et al. 2017).

References

IUCN SSC Amphibian Specialist Group. (2021). "Pristimantis aureoventris." The IUCN Red List of Threatened Species 2021: e.T46086220A86255408. https://dx.doi.org/10.2305/IUCN.UK.2021-1.RLTS.T46086220A86255408.en

Jablonski, D., Grula, D., Barrio-Amoros, C., Kok, P. (2017). "Molecular phylogenetic relationships among Pristimantis summit populations in the eastern tepui chain: insights from P. aureoventris (Anura: Craugastoridae)." Salamandra 53(3): 473-478. [link]

Kok, P. J. R., Means, D. B., Bossuyt, F. (2011). "A new highland species of Pristimantis Jiménez de la Espada, 1871 (Anura: Strabomantidae) from the Pantepui region, Northern South America." Zootaxa 2934(1): 1-19. [link]

Species Account Citation: AmphibiaWeb 2022 Pristimantis aureoventris <https://amphibiaweb.org/species/7693> 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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