Researchers find 6 colour morphs of Shillong Bush frog

SHILLONG : Meghalaya’s smallest frog ‘the Shillong bush frog’ endemic to the state’s higher reaches of East Khasi Hills district exists in many vibrant colour morphs, researchers said on Sunday. They said the frog—the size of which is so small that it can comfortably sit on a fingernail— was recently discovered to exist in at least six different colour schemes in their bodies.

Researchers of the Zoological Survey of India—Bhaskar Saikia and Ilona Kharkongor ‘ whose research was published by the Herpetological Review— a peer-reviewed quarterly that publishes articles and notes concerning the study of amphibians and reptiles, said they encountered several vibrant colour morphs of the species during their evening stroll in the Reserve Forest along the slope south of the city.

Except for the white patches on the supra tymphanic folds and the dark inter-orbital mark, some of the observations made were that some of the species have a grey dorsum, dark brown dorsum, black dorsum, hourglass marking on dorsum and a grey or slaty dorsum. Endemic to Shillong and the higher altitudes of East Khasi Hills district, the male frogs make a distinct ‘tick-tick’ sound calling for their mates during the wet summer evening.

What makes the Shillong Bush frogs different and unique from other frogs apart from the small size of their bodies is that these frogs have a direct development, Saikia said. The embryos develop directly into juveniles within the eggs as the species forgo the tadpole stage and hatch as tiny froglets, a miniature version of their parents, he said. This evolutionary strategy removes their need for water during the stages of development, he added. Another researcher, N Srinivas, expressed regret that urbanisation could wreak havoc on the tiny frog species of Meghalaya. He said,

‘The Shillong bush frog shares space with the people and this exposes it to a range of threats like pollution, concretisation, and habitat fragmentation.’ Forest fires, unregulated tree felling, mining, garbage disposal at forest edges, and utilisation of harmful pesticides in gardens “all these are also threats unique to the Shillong bush frogs,” he said. These, coupled with a narrow distribution range, and the ever-looming threat of climate change and global warming, is why these endemic high elevation species are critically endangered, he noted.