Description
Description: The snout-vent length for adult males of this species is 19.2 mm to 20.8 mm and in females, SVL ranges from 25.1 mm to 25.3 mm. The head is almost equal in width and length and appears flat from above. The slightly protruding snout is pointed in dorsal view, and rounded in profile view, with a rounded canthus rostralis and acutely concave loreal region. The concave interorbital area is wider than the internarial distance. Nostrils are oval and are closer to the tip of the snout than to the anterior of the eye. The pupil is oval. The tympanum is distinct and rounded and is larger in diameter than the eye, with a distinct supratympanic fold running from the posterior of the orbit to the shoulder. The large, cordate tongue is smooth and deeply emarginate with obtuse lobes. Forelimbs are shorter than the hands. Relative lengths of fingers are I < II < IV < III. Each finger tip has a disc with circum-marginal grooves. All fingers lack lateral dermal fringe and webbing. Rounded subarticular tubercles are prominent, and all fingers have supernumerary tubercles. The rounded prepollex is distinct. There is a single, distinct, oval palmar tubercle. Hind limbs are moderately long, and the heels almost touch when adpressed. The tibia is about 3.3x longer than wide, and is shorter than the thigh. Relative lengths of the toes are I < II < III < V < IV. Tips of the toes are wide in comparison to the widths of the toes. Each toe tip has a disc with a distinct circum-marginal groove. Webbing between the toes is small, and dermal fringe is present along toe V. Simple, rounded subarticular tubercles are prominently present on all toes, although tubercles 2 and 3 on toes IV and 2 on toe V are weakly developed. The oval inner metatarsal tubercle is distinct, and more than twice the the length of the toe. The skin texture of the snout and between the eyes is shagreened with tubercles. Upper eyelids are slightly granular, while the tympanic region is quite granular. The dorsum, flanks, thigh and tibia are granular. Dorsal surfaces of the forelimbs transition from shagreened to sparingly granular in texture, while the ventral surfaces of the forelimbs are granular. The tarsus is shagreenend also. The throat texture varies from shagreened to granular. The chest, belly and posterior surfaces of the thighs are all granular. Males possess a median subgular vocal sac, and have a pair of openings at the base of the lower jaw. In females the oviduct is zig-zagged and translucent (Biju and Bossuyt 2006).

Dorsal surfaces are a pale gray-green highlighted with a silver and cobalt-violet tinge (Biju, Bossuyt 2006). The dorsum is marked by a dark gray upside-down "V" which runs from the eye to the vent. The dorsum and the flanks are marked by black, brown, silver and violet spots of various sizes. Loreal and temporal regions are brown-black. The iris is a gold brown with a distinct green-brown outer ring, and the pupil has a golden outer ring. Limbs have black cross bands over light grayish brown. Fingertips are white. The femur area is coffee-brown colored with varying concentrations of dark and light spots and patches. Sides of the belly are marked by light yellow-brown blotches. The ventral surfaces of the thigh, tibia, and tarsus are predominantly grey-brown mixed with brown blotching. Feet and hands are dark gray-brown with black spots. In preservative the dorsum is a lighter gray-brown with black and gray spots scattered throughout (Biju and Bossuyt 2006).

Diagnosis: This species can be diagnosed from other species in the genus by the following combination of characters: small adult size (male SVL less than 20.8 mm), elongated body, tibia longer than foot, well-developed supernumerary tubercles on all toes, granular flanks and dorsum, coarsely granular forelimb underside, and femur coloration (coffee-brown with variable light brown to yellowish-brown blotches).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: India

View distribution map in BerkeleyMapper.

Endemic to India. Currently known only from the type locality at Kodaikanal, in Dindigal Anna District, Tamil Nadu State, in the southern Western Ghats of India, at elevations of 1,900 m - 2,300 m asl. The locality is south of the Palghat Gap. Inhabits grassland and adjacent fringes of shola forest (Biju and Bossuyt 2006).

Life History, Abundance, Activity, and Special Behaviors
Collected specimens were gathered during a rainstorm at night, about one meter above ground in roadside shrubs (Biju and Bossuyt 2006).

In females, the ovary is large and creamy white in color. Ovarian eggs were about 3 mm in diameter in one specimen (Biju and Bossuyt 2006).

Larva
This species is a direct developer (Biju 2006).

Trends and Threats
This species is abundant and can tolerate disturbed habitat, as it is found not only in rainforest but in roadside vegetation and gardens (Biju and Bossuyt 2006). It is not known to occur within any protected areas (Biju 2006).

Comments
Raorchestes dubois is named after Alain Dubois, of the Paris Museum of Natural History in France, as an expression of gratitude and appreciation for his contributions to batrachological research and guidance to the species discoverers, S. D. Biju and Franky Bossuyt, in establishing their initial research projects (Biju and Bossuyt 2006).

References

Biju, S. D. (2006). Philautus duboisi. In: IUCN 2010. IUCN Red List of Threatened Species. Version 2010.1. www.iucnredlist.org. Downloaded on 05 May 2010.

Biju, S. D., and Bossuyt, F. (2006). ''Two new species of Philautus (Anura, Ranidae, Rhacophoridae) from the Western Ghats, India.'' Amphibia-Reptilia, 27, 1-9.

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.

Species Account Citation: AmphibiaWeb 2022 Raorchestes dubois: Kodaikanal Bush Frog <https://amphibiaweb.org/species/6730> University of California, Berkeley, CA, USA. Accessed Nov 19, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 19 Nov 2024.

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