GUWAHATI
The newest croaker recorded in India is a dark cave dweller, unlike most members of the Ranidae family belonging to Amolops, a genus of true frogs.
Scientists from the Shillong and Pune units of the Zoological Survey of India (ZSI) have named the new species Amolops siju after the Siju cave system of Meghalaya, from where four specimens were collected. Two of them, including a gravid female, were found in a dark zone of the cave near a chamber of bats.
This is the second cave-dwelling species of frog recorded from India after Micrixalus spelunca in Tamil Nadu nine years ago.
Amolops siju has been described in the latest issue of the Journal of Animal Diversity. The authors of the study are Bhaskar Saikia and Bikramjit Sinha of ZSI, Shillong, and K.P. Dinesh and Shabnam Ansari of ZSI, Pune.
“Frogs are known to inhabit the subterranean world of caves due to the constant humidity and temperature that a cave ecosystem provides. However, what is extremely rare is the discovery of a new species of frog from a cave,” Mr. Saikia said.
The Amolops siju is the first cave-dwelling cascade frog from the northeast. It has been named after Siju, a 4-km-long natural cave in Meghalaya’s south Garo hills district.
Cascade frogs being morphologically cryptic in nature, tissue samples of the specimens were subjected to molecular studies to ascertain their specific identity from the other known species. Based on the morphological, molecular and spatial data, the ZSI team concluded that this population of frogs from Siju cave, was new to science.
Although the specimens were collected from the twilight (60-100 m from the cave entrance) and the dark (beyond 100 m of cave entrance) zones of the cave, the team did not find any troglobitic or cave-adapted modification. This suggested that Amolops siju is not a permanent resident of the cave, Dr. Dinesh said.
There have been reports of the presence of frog populations up to 400 m from the cave entrance since 1992, when the ZSI conducted the first bio-speleological exploration in Siju cave.
The cave is known to harbour more than 100 faunal species, mostly invertebrates like cave crickets, spiders, beetles, and earthworms.
Amolops siju is the fourth species of cascade frog described from the northeast by the quartet of Mr. Saikia, Dr. Sinha, Dr. Dinesh and Ms. Shabnam. They had earlier described Amolops Chanakya, Amolops terraorchis, and Amolops tawang from Arunachal Pradesh.
“Frogs are known to inhabit the subterranean world of caves due to the constant humidity and temperature that a cave ecosystem provides” Bhaskar SaikiaAuthor, Journal of Animal Diversity
