Description
Stumpffia staffordi is a large frog for its genus that was described from two males with snout-vent lengths of 27.0 and 27.9 mm. The canthus rostralis is rounded. The eye is relatively large, being twice the width of the tympanum. The tympanum is not easily visible. The limbs are slender. There is a distinct, enlarged inner palmer tubercle that protrudes to the side of the hand. There is no webbing between the fingers and all fingers and toes are fully formed. The round tips of the fingers and toes are enlarged. The skin is smooth with occasional round protrusions (Köhler et al. 2010).

DIAGNOSIS:

Stumpffia staffordi is differentiated from S. analamaina, S. angeluci, S. gimmeli, S. huwei, S. iharana, S. larinki, S. madagascariensis, S. maledicta, S. mamitika, S. miery, S. psologlossa, S. pygmaea, S. sorata, S. tetradactyla, S. tridactyla, and S. yanniki by its larger body and larger discs on fingers (Rakotoarison et al. 2017). Stumpffia staffordi is differentiated from S. be by the missing red coloration on hidden areas of the hind limbs. Additionally, they can be differentiated from S. megsoni by its larger size, and from S. hara by its missing white spotting on the venter (Köhler et al. 2010).

COLORATION:

In life, the dorsal side of the body and limbs, the posterior side of thighs, the throat, and the loreal and tympanal regions are all brown. The interorbital bar is dark brown. The dorsal side of the head is greyish brown with a hint of metallic green. The belly and the ventral side of the thighs are bluish grey. Irregular dark flecks are spread across the limbs, the loreal region, and the tympanal region. White flecks are present on the throat and lower flanks. The eyes have a black iris with speckles of copper (Köhler et al. 2010).

In preservative, the dorsal side of the body, the dorsal side of the hind limbs, and the posterior side of thighs are tan. The head and loreal region are brown. The belly is cream colored. The flanks are light brown with pale spots. Brown spots are spread across the cloacal region, chest, throat, forearms, and dorsal side of body. A few white spots are spread across the chest and throat. The eyelids are grey (Köhler et al. 2010).

VARIATION:

The two specimens used for the species description are identical except for slightly different snout-vent lengths (Köhler et al. 2010).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: Madagascar

View distribution map in BerkeleyMapper.

Stumpffia staffordi is distributed in the Montagne des Français Reserve in northern Madagascar. The species was found in a single, terrestrial, non-aquatic cave characterized by pointed, karstic rock formations and the presence of small puddles. The species' range has an elevation limit of 260 meters and is restricted to subterranean caves and crevices of cave formations (Köhler et al. 2010).

Life History, Abundance, Activity, and Special Behaviors
Stumpffia staffordi is terrestrial and was found in a karstic cave, perched on the edge of a puddle deep within the cave. This species is rare and is only known from a small number of individuals (Köhler et al. 2010, Rakotoarison et al. 2017).

When under distress, the species emits high-pitched vocalizations. The frequency and length of instances of vocalization do not occur with a consistent pattern, with the time between calls ranging from 11 - 42 ms and the frequency of calls ranging from 2000 - 9400 Hz (Köhler et al. 2010).

Two prominent features of S. staffordi are their wide heads and large eyes. These features are found in a few other Stumpffia species as well. Studies on these species are limited but these features are believed to be adaptations to the consumption of large prey and to the dark caves they live in (Köhler et al. 2010).

Trends and Threats
Threats of deforestation and agriculture currently do not pose a threat as the species is primarily restricted to cave habitats. However, the degradation of surrounding ecosystems may exacerbate habitat loss, potentially driving the species to "Critically Endangered" or "Extinct" status (IUCN 2020).

Possible reasons for amphibian decline

General habitat alteration and loss

Comments

PHYLOGENETIC RELATIONSHIPS:

Phylogeny generated using Bayesian Inference based on the 12S rRNA and 16S rRNA genes indicate that S. staffordi is the sister species to a clade containing three other large sized Stumpffia species: Stumpffia be, Stumpffia hara, and Stumpffia megsoni (Köhler et al. 2010).

ETYMOLOGY

Stumpffia staffordi is named after herpetologist Peter Stafford who spent his career studying squamates in Mesoamerica (Köhler et al. 2010).

References

IUCN SSC Amphibian Specialist Group. (2020). "Rhombophryne staffordi (amended version of 2016 assessment)." The IUCN Red List of Threatened Species 2020: e.T49585498A177168567. https://dx.doi.org/10.2305/IUCN.UK.2020-3.RLTS.T49585498A177168567.en. Accessed on 20 February 2022.

Köhler, J., Vences, M., D'Cruze, N., and Glaw, F. (2010). "Giant Dwargs: discovery of a radiation of large-bodied 'stump-toed frogs' from karstic cave environments of northern Madagascar." Journal of Zoology, 282, 21-38. [link]

Rakotoarison, A., Scherz, M.D., Glaw, F., Köhler, J., Andreone, F., Franzen, M., Glos, J., Hawlitschek, O., Jono, T., Mori, A., Ndriantsoa, S.H., Raminosoa, N.R., Riemann, J.C., Rödel, M., Rosa, G.M., Vieites, D.R., Crottini, A., Vences, M. (2017). "Describing the smaller majority: integrative taxonomy reveals twenty-six new species of tiny microhylid frogs (genus Stumpffia) from Madagascar." Vertebrate Zoology, 67(3), 271-398. [link]

Species Account Citation: AmphibiaWeb 2022 Stumpffia staffordi <https://amphibiaweb.org/species/7542> 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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