Description
Diasporus darienensis is a small, slender frog that is a member of the Eleutherodactylid rain frogs. Males tend to have a snout-vent length between 14.9 - 18.5 mm and females are between 18.5 - 22.9 mm. The head is about as wide as it is long with the width at the angles of the jaw ranging between 5.2 – 8.4 mm and head length running from 5.6 – 7.9 mm. The snout is subacuminate in the dorsal view and rounded when viewed from the profile. The dorsolaterally directed nostrils are at the tip of the snout, making them visible from the front and dorsally, but obscured ventrally. The canthus rostralis is rounded and the loreal region is slightly concave. The eye is two times the length of the snout. Individuals usually have a conical shaped tubercle in the superocular region. The moderate but indistinguishable tympanum is located above the junction of the jaws. The tympanic annulus is covered by skin and lacks a tympanic membrane. This species lacks a cranial crest. The appearance of the dentigerous processes in the vomer is triangular. Vocal slits are located on the posterior part of the jaw. Texture of the dorsal skin is smooth with dispersed tubercles that can look either rounded or sharp. The skin on the ventrum is smooth with the exception of low warts in the anal region. There is no obvious discoidal fold (Batista et al. 2016).

The hands are moderately size at 20% of the snout-vent length. There is a low, round palmar tubercle that is larger than the low, elongated thenar tubercle. There are no other distinguishable accessory tubercles on the palms. The relative length of the unwebbed, fringeless fingers is I < II < IV < III with finger II almost the same length as finger IV and reaching its disc. The fingers have even, broadened discs with finger III having a disc that is 1.6 times wider than the fingertip below it. Round, globular subarticular tubercles are present but there are no supernumerary tubercles. The fingers lack nuptial pads but have broad, globular fingertip pads (Batista et al. 2016).

The hindlimbs are of moderate length at 43% of the snout-vent length. The inner metatarsal tubercal is ovoid and larger than the slightly pointed outer metatarsal tubercle. There are no other accessory plantar tubercles, and there is no tarsal ridge. The almost rounded ungual flap is expanded. Like the fingers, the toes are unwebbed, fringeless, and end in evenly broadened discs. The relative toe lengths are I < II < III < V < IV with one subarticular tubercle on toes I and II, two tubercles on toes III and V, and three tubercles on toe IV. The pads of the toe tips appear globular and broad in the profile view (Batista et al. 2016).

Diasporus darienensis can be distinguish from some members of its genus by the shape of its ungual flap on the anterior margin of the toe pad, which is spade-like or rounded, does not have papillae, and is the most conspicuous on fingers II – IV. For more similar species, D. darienensis can be differentiated from D. tigrillo by the former having a pale brown to red dorsum instead of yellow to orange. From central and eastern Panama populations of D. diastema, D. darienensis is differentiated by having a reddish dorsal pattern with pale lines or blotches. From its sister species, D. majeensis, D. darienensis can be differentiated by the venter being pigmented (Batista et al. 2016).

In life, the dorsal coloration is brown to reddish and can be plain or have a lighter reticulated pattern. There is typically a pair of red or light buff dorsolateral stripes. The lower back can be a tawny color and the flanks are brick red. The ventrum of the frog can be translucent or have a gradation of darker color. The vocal sac is colored yellow and has longitudinal gular folds. The ventral region, especially the groin and up to the axilla have a brick-red, mottled pattern. The iris is a light rufous and patterned with irregular, lateral tawny lines. In preservation, the dorsal coloration is dull amber, and the dorsolateral stripes are buff colored. The venter and groin are also buff colored with slightly darker speckling. The ungula flaps are a dark color (Batista et al. 2016).

There is variation in coloration within individuals of the species (Batista et al. 2016).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Panama

View distribution map in BerkeleyMapper.

This species is found in the tropical montane cloud forests of Eastern Panama. Their distribution encompasses the Panamanian districts of Pinogana, Sambú, and Garachiné in the province of Darién. The forests they can be found in have plant communities composed of orchids, bromeliads, giant ferns, and moss. Their elevational range is from 869 – 1169 m above sea level (Batista et al. 2016).

Life History, Abundance, Activity, and Special Behaviors
Diasporis darienensis is nocturnal and arboreal, usually found 1 – 5 m above ground. This height range was higher than any of the known species in Diasporis at the time D. darienensis was described (Batista et al. 2016).

During the daytime, these frogs are known to take shelter in bromeliad leaves. At night they are active and move between the bromeliads and the trunks of trees in the forest (Batista et al. 2016).

Males have been seen calling from branches or leaves in trees at the end of the rainy season (December). Their call consists of one short, monophasic, whistle-like note with a modulated amplitude. Note duration ranged between 49.1 – 51.7 ms, and call intervals lasted between 16.91 – 16.25 s. The call rate is four calls per minute. The peak frequency ranges between 2.79 – 4.30 with the dominant frequency of the first harmonic ranging between 3.34 – 3.81 kHz (Batista et al. 2016).

The diet of this frog is not known yet, but is presumed to consist mainly of arthropods like its close relatives (Batista et al. 2016).

Trends and Threats
Abundance hasn’t been officially reported for this species, given their geographic range, chytrid fungus could be threat. Habitat loss in Eastern Panama has also been recorded in recent years and could potentially also affect this species (Parker et al. 2004).

Possible reasons for amphibian decline

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

Comments
The species authority is: Batista, A., Kohler, G., Mebert, K., Andreas, H., Milan, V. (2016). “An integrative approach to reveal speciation and species richness in the genus Diasporus (Amphibia: Anura: Eleutherodactylidae) in eastern Panama.” Zoological Journal of the Linnean Society. 178, 267–311.

Based on Bayesian Inference analysis of 16S, COI, and RAG1 genes, Diasporus darienensis is the sister taxon of D. sapo and along with D. majeensis form a Darién highlands clade within Diasporus (Batista et al. 2016).

The species epithet “darienensis” is derived from where the holotype was found, in the Panamanian province of Darién (Batista et al. 2016).

Frogs in the genus Diasporus were previously classified to be under the Eleutherodactylus diastema group (Hedges et al. 2008). Members of Diasporus are part of a cryptic complex of frogs, and there is the potential of there being more undescribed species (Hertz et. al. 2012).

References

Batista, A., Kohler, G., Mebert, K., Andreas, H., Milan, V. (2016). ''An integrative approach to reveal speciation and species richness in the genus Diasporus (Amphibia: Anura: Eleutherodactylidae) in eastern Panama.'' Zoological Journal of the Linnean Society, 178, 267-311.

Hedges, S. B., Duellman, W. E., Heinicke, M. P. (2008). ''New World direct-developing frogs (Anura: Terrarana): Molecular phylogeny, classification, biogeography, and conservation.'' Zootaxa, 1737, 1-182.

Hertz, A., Hauenschild, F., Lotzkat, S., Köhler, G. (2012). ''A new, golden frog species of the genus Diasporus (Amphibia, Eleutherodactylidae) from the Cordillera Central, western Panama.'' ZooKeys, 196, 23–46.

Parker, T., Carrión, J., Samudio, R. (2004). “Environment, biodiversity, water, and tropical forest conservation, protection, and management in panama: assessment and Recommendations.” Biodiversity and tropical forestry assessment of the USAID/PANAMA Program. Washington, PA: Chemonics International Inc. Task Order# 824, BIOFOR IQC No. LAG - I - 00 - 99 - 00014 - 00.

Species Account Citation: AmphibiaWeb 2018 Diasporus darienensis: Darien dink frog <https://amphibiaweb.org/species/8579> 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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