Description
Morphology: Ghatixalus asterops is a medium-sized frog with SVL ranging from 38.8 mm – 44.8 mm in males, and 58.1 mm in a single collected female specimen from Kodaikanal. The snout is rounded in lateral view but in dorsal view, the snout is pointed and protrudes slightly. The body is robust. Eyes have horizontal, oval-shaped pupils and a distinctive star-shaped pattern on the iris. The tympanum is rounded and clearly visible. A distinct, supratympanic fold runs from the posterior side of the eye to the upper portion of the forearm. The hand is longer than the forelimb. Fingers are moderately webbed and have fringe on both edges as well as discs with circummarginal grooves. There is a moderate amount of webbing present. Lengths of fingers, from longest to shortest: III>IV>II>I. Each finger has a single, round, distinct subarticular tubercle and numerous supernumerary tubercles, particularly fingers III and IV. A distinct oval prepollex is present. The palmar tubercle is round and distinct. Toes are extensively webbed, with prominent subarticular tubercles but lacking supernumerary tubercles. No fringe is present on toe V. The relative length of toes from longest to shortest is IV>V>III>II>I. The inner metatarsal tubercle is distinct and oval. Skin on the dorsum is shagreened and slightly granular. Forelimbs, legs, tarsi, and thighs are shagreened dorsally. Ventrally, the throat and chest vary from shagreened to grainy. Males have a white, weakly spinose nuptial pad on finger I and a single vocal sac. The sole female specimen had a more granular skin texture and larger subarticular and supernumerary tubercles.

Coloration: Varies between localities. Dorsally, this species may have irregularly patterned brown blotches on a dark or light gray background, or reddish brown blotches on a yellowish brown background. Loreal and tympanic areas are light gray with brown spotting. Sides are yellow with brown patches. Hand and foot are light bluish-white with bluish-brown blotches present on the webbing. The posterior thigh is bluish-brown. The iris is brownish with golden stripes in the shape of a star and a slender golden ring around the periphery. Limbs are dark gray with dark brown bars. Fingers and toes are barred and have light gray tips.

Juveniles: Juvenile frogs vary from light green to light brown. Adults are never green.

Similar species: Distinguished from G. variabilis by the star-like eye pattern (uniform brown in G. variabilis), pointed snout (vs. oval), acute loreal region (vs. obtuse), shorter supratympanic fold extending to upper forearm (vs. extending to just below upper forearm level), and a longer shank equal to the thigh length (vs. shorter than thigh length).

Distribution and Habitat

Country distribution from AmphibiaWeb's database: India

View distribution map in BerkeleyMapper.

Endemic to the Western Ghats of India. The frog is present in montane areas and has been observed at two localities, near the border of Kodaikanal (Tamil Nadu) and Mattupetti (Kerala), from 1,700 m to 2,000 m above sea level. It is restricted to disturbed evergreen sholas (isolated patches of montane forest).

Life History, Abundance, Activity, and Special Behaviors
The species is found near montane streams. It prefers terrestrial habitat, inhabiting grass patches, rock patches, leaf litter, and shrubs. It hides in water for minutes when disturbed, an unusual characteristic since rhacophorid treefrogs usually stay away from water except during mating season.

In late summer, August to September, male calling occurs after 6:00pm. Calls consist of a series of five to seven whistle-like notes (phu phu phu phu phu phu phu), repeated every two to three minutes.

Amplexus is axillary. Foam nests are constructed on rocks, vertical earth surfaces of stream banks, and occasionally on the bases of trees adjacent to the stream, suspended up to 3 m above the water. The nests are spherical in shape. Eggs are white and measure 2.8 mm in diameter. Tadpoles hatch and fall into the body of water four days after egg deposition. Hatching success rate was 78.7% in 185 eggs from a single nest.

Trends and Threats
Habitat fragmentation is a major threat since the species is restricted to disturbed and isolated patches of montane forest (evergreen sholas).

Possible reasons for amphibian decline

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

Comments
"Aster" means star and "ops" means eyes in ancient Greek. The star-like patterning of the iris gives the eye a distinctive appearance.

References

Biju, S. D., Roelants, K., and Bossuyt, F. (2008). ''Phylogenetic position of the montane treefrog Polypedates variabilis Jerdon, 1853 (Anura: Rhacophoridae), and description of a related species .'' Organisms, Diversity, and Evolution, 8(4), 267-276.

Species Account Citation: AmphibiaWeb 2009 Ghatixalus asterops <https://amphibiaweb.org/species/7266> University of California, Berkeley, CA, USA. Accessed Oct 11, 2024.

Citation: AmphibiaWeb. 2024. <https://amphibiaweb.org> University of California, Berkeley, CA, USA. Accessed 11 Oct 2024.

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