Kingdom Animalia Family Rhacophoridae Phylum Chordata Order Frog | Class Amphibia Species M. myristicapalustris Rank Genus | |
Similar Frog, Raorchestes, Pseudophilautus, Frankixalus, Taruga | ||
Mercurana is a genus of arboreal frogs belonging to the family Rhacophoridae. The genus was named from the only known species Mercurana myristicapalustris, which was described in 2013 from the Western Ghats of Kerala, India. The generic name was derived from and given as a tribute to Freddie Mercury, the late vocalist of the British rock band Queen, in combination with the Latin name for "frog" (Rana, which is also the name of the most common frog genus). The frog is different from other related frogs in that it has extensively webbed toes, lives only in swampy lowlands, and lays its eggs on mud with which it carefully mixes leaf litter.
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Discovery and etymology
The type species (holotype) of Mercurana was collected on 18 May 2012 from bushes at the periphery of a temple compound, Arippa, near Kulathupuzha Reserve Forest, Kollam district, Kerala, India. It was a single adult male. Other two adult males (paratypes) were found from the same locality on 12 July 2012. The formal description was published on 17 April 2013 in the journal Zootaxa. The generic name was derived from ‘Mercury’ as a tribute to Freddie Mercury, the late singer and lyricist of the British rock band Queen, in combination with the genus name Rana, the most common frog taxa. The scientists chose 'Mercury' because Mercury's "vibrant music was inspiring", in the author's own account. Further, Mercury was of an Indian-Parsi origin and spent majority of his childhood in Panchgani, which is located in the northern part of the mountain range from where the frog was discovered. The specific name is a combination of the words Myristica (a genus of the nutmeg family of trees), and palustris, which is Latin for "swampy", to indicate the swamp forest habitat dominantly represented by Myristica trees in which the frog lives. The forest is particularly noted for its fragile and threatened habitat type in the Western Ghats.
Description
Mercurana are medium-sized frogs; males are smaller measuring 35 mm in length, while the female is up to 65 mm. They have a slender body which is rusty-brown in colour with small black speckles on the back. Females are more greenish-yellow in colour on the back. The dorsal surface of the skin is a rough shagreen. The ventral (front) side is gradually lightened and becomes mostly white. Some areas of the underside of the fore-and hind-limbs have patches of yellow colour. The chest, belly and throat are glandular. The snout is rounded and protruding. Unlike other related species, Mercurana has large webbed toes, while the fingers are free with large discs, and is characterised by the presence of vomerine teeth and lingual papilla. They have distinct dark eyes, with horizontal and oval-shaped pupil.
Biology
Mercurana are arboreal frogs and live in lowland swamp forest. They breed during the pre-monsoon. During the breeding season, males call females at sunset while perched above the water or stream, generally 2–5 m above the forest floor. Then they descend to the ground awaiting for the female. Sometimes males engage in combat with each other for optimal perching sites. After amplexus, the mating pair then move into the leaf litter where they gradually change their body colour so as to blend with their surrounding environment. The female then digs a shallow burrow in the soil and lays eggs, mixing them with mud using her hind feet. Early embryonic development occurs in moist mud after the pre-monsoon rains. The tadpoles are free-living and aquatic.
Distribution
Mercurana is endemic to India. The monotypic species Mercurana myristicapalustris has been documented only in the western foothills of the Agasthyamalai Hill Range in Kerala. The habitat preference is also strictly the low-elevation of swampy forest (100 to 300 m asl) dominated by Myristica trees.