Description
Diagnosis: Raorchestes ponmudi has a snout-vent length (SVL) that ranges from 35.9-38.9 mm, with males being larger than females. R. ponmudi can be characterized by the presence of protruding eyes, the presence of lingual papillae, prominent nuptial pads in males and the presence of bands on the posterior surfaces of the shanks. It is a robust frog and can be distinguished from other Western Ghats species by the vermiculated posterior surfaces of the shanks. The SVL is greater than all other similar anuran species in the area. It has a sharp canthus rostralis, as well as webbing of the toes that reaches the distal subarticular tubercle on either side of toe IV (Biju and Bossuyt 2005; Biju and Bossuyt 2009).

Description: The snout is longer than the horizontal diameter of the eye. The nostrils are oval, lack a distinct lateral skin flap, are slightly raised, and are located closer to the tip of the snout than the eye. The pupils are horizontal and oval, and the tympanum is distinct, round, and is approximately three times larger in diameter than the eye. Tympanum size is equal to the tympanum-eye distance. R. ponmudi lacks vomerine teeth. It has a large tongue, along with obtuse lobes that are sparsely granular. Lingual papillae are present and pointed, and the supratympanic fold is distinct. The hand is longer than the forelimb, and the relative lengths of the fingers in increasing order, are as follows: I, II, IV, III (Biju and Bossuyt 2005).

Coloration: There is a pair of brown concave stripes that runs from behind the eye to the vent and crosses in an "X" pattern on the back, and the dorsum is a light gray-yellow with some white blotching and small black splotches. The thighs are a light chocolate brown and are vermiculated with gray patches that differ in size. Between the eyes, there is a light brown triangle which extends to the upper eyelid. The snout, loreal region, and tympanic region are all light brown, with dark gray upper eyelids. R. ponmudi has a light grey groin with dark brown spots. The eye is golden brown and encircled in a grey ring. The lips are brown banded. The forelimbs have dark brown spots and are light brown, and the hind limbs are light brown with gray cross bands. The posterior of the thigh is light chocolate brown and is vermiculated with patches of grey. The ventral surface is light, gray and the throat is dark gray with dark brown spots. The ventral sides of the feet are light gray, with the tibia being light chocolate brown and vermiculated with light green patches (Biju and Bossuyt 2005).

Variation: The dorsal coloration does not vary greatly, but may fade upon preservation. The "X" pattern on the dorsal surface can be faded on some individuals (Biju and Bossuyt 2005).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: India

View distribution map in BerkeleyMapper.

The species is found at Ponmudi Hill, which is a part of the Agasthyamala Hill Range in the Western Ghats in India. Most specimens have been collected from an evergreen forest that is surrounded by grassland at 1000 m elevation (Stuart et al. 2008). R. ponmudi has been found between 8-15 m in the forest canopy (Biju and Bossuyt 2009). However, other individuals have been observed 2-4 m off the ground on coffee plants, rather than in the forest canopy.

Life History, Abundance, Activity, and Special Behaviors
Most individuals were collected from forest canopy, suggesting that an arboreal habitat is preferred. When specimens were collected, individuals were observed calling and were nocturnally active (Biju and Bossuyt 2005).

Larva
Its reproductive mode is characterized by direct development (Stuart et al. 2008).

Trends and Threats
The one known population is declining, possibly due to habitat loss caused by the expansion of tea plantations. As it is only found inside a limited range, and this range is threatened, its status is "Critically Endangered" (Stuart et al. 2008).

Possible reasons for amphibian decline

General habitat alteration and loss
Habitat modification from deforestation, or logging related activities
Intensified agriculture or grazing

Comments
Species Authority: The species was described by Biju and Bossuyt (2005).

Phylogenetic Relationships: R. ponmudi is a member of the Rhacophorid family. It was originally classified in the genus Philautus, but was subsumed into a new genus, Raorchestes, based upon recent molecular evidence (Biju et al. 2010).

Etymology: This species has been named after the area in which the type specimens were found, Ponmudi Hill in the Western Ghats of India (Biju and Bossuyt 2005).

References

Biju, S. D., Shouche, Y., Dubois, A., Dutta, S. K., and Bossuyt, F. (2010). "A ground-dwelling rhacophorid frog from the highest mountain peak of the Western Ghats of India." Current Science, 98(8), 1119-1125. [link]

Biju, S. D., and Bossuyt, F. (2009). ''Systematics and phylogeny of Philautus Gistel, 1848 (Anura, Rhacophoridae) in the Western Ghats of India, with descriptions of 12 new species.'' Zoological Journal of the Linnean Society, 155, 374-444.

Dinesh, K. P., Radhakrishnan, C., Gururaja, K. V., and Bhatta, G. (2009). ''An annotated checklist of Amphibia of India with some insights into the patterns of species discoveries, distribution and endemism.'' Records of the Zoological Survey of India, Occasional Papers, 302, 1-153.

Inger, R. F., Shaffer, H. B., Koshy, M., and Bakde, R. (1984). ''A report on a collection of amphibians and reptiles from the Ponmudi, Kerala, South India. Part 1.'' Journal of Bombay Natural History Society , 81(2), 406-427.

Inger, R. F., Shaffer, H. B., Koshy, M., and Bakde, R. (1984). ''A report on a collection of amphibians and reptiles from the Ponmudi, Kerala, South India. Part 2.'' Journal of Bombay Natural History Society , 81(3), 551-570.

Stuart, S., Hoffmann, M., Chanson, J., Cox, N., Berridge, R., Ramani, P., Young, B. (eds) (2008). Threatened Amphibians of the World. Lynx Edicions, IUCN, and Conservation International, Barcelona, Spain; Gland, Switzerland; and Arlington, Virginia, USA.

Species Account Citation: AmphibiaWeb 2022 Raorchestes ponmudi: Large Ponmudi Bush Frog <https://amphibiaweb.org/species/6652> 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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