Researchers have found a new tadpole that occasionally eats sand and spends a great deal of its life underground in the Western Ghats of India. The team was rather surprised to discover the frog burrowing through sand, as this is highly uncharacteristic for the species.
According to the scientists from Gettysburg College, University of Delhi, and the University of Peradeniya, the new tadpoles are part of the Indian dancing frog family, Micrixalidae. Field observations showed they were found hiding in the “deep recesses of streambeds, where they live in total darkness until they fully develop into froglets.”
After conducting genetic analyses, the group established these were Micrixalus herrei – the first tadpoles of Indian Dancing frog family confirmed by scientists.
Prof. SD Biju from the University of Delhi said one reason why these tadpoles remained unnoticed is their fossorial nature, which is a very rare occurrence among amphibians.
Scientists knew very little about Indian dancing frogs, just that they mark their territory and attract potential mates by waving their legs while perched on a boulder. Other than that, tadpoles from this particular family had remained a mystery over the years.
According to the group’s description, the new kind of tadpoles has “muscular eel-like bodies” and their eyes are protected by skin so they can burrow through gravel beds. They have no teeth, but their mouthparts are covered with filter-like jaw sheaths that prevent large sand particles from entering the mouth.
However, researchers discovered that the amphibian’s gut does contain some decaying organic matter and small sand grains which might be an alternative nutrient source.
During the earlier stages of their development, tadpoles have ribs, which help protect their internal organs. Studying the tadpoles’ external morphology suggested that the ribs could facilitate underground movement.
One of the study researchers from the University of Peradeniya, Madhava Meegaskumbura, said that “only four families of frogs are reported to have ribs.” She added that this adaption of the tadpoles in the Micrixalidae “may provide for greater muscle attachment, helping them wriggle through sand.”
Meanwhile, researchers also discovered that the juvenile frogs also had whitish “lime sacs” that acted as storage space for calcium carbonate – which is rather uncommon for this species.
The study, which was recently featured in the journal PLOS ONE, highlights the “uniqueness of amphibians” located in the biodiversity offered by the Western Ghats. The team hopes their findings prompt future studies on the elusive frogs.
Image Source: BBC News