Sand Burrowing Tadpole Discovered in India

Posted on March 31, 2016

Micrixalus herrei tadpoles

A tadpole that can burrow through sand has been found in streambeds in the Western Ghats of India. The tadpoles remained buried in deep recesses of streambeds until they develop into froglets. They live in total darkness during this time period.

The tadpoles of Micrixalus herrei belong to the Indian Dancing frog family. They have several unique traits that make it possible for them to burrow in live in recesses in the sand. These traits include a muscular eel-like body and skin covered eyes. They also have jaw sheaths which helps prevent large sand grains from entering the tadpole's mouth. The tadpoles are capable of ingesting some sand. They also have ribs which protect the internal organs and facilitate underground movement. The tadpoles also have lime sacs which can act as a source of calcium carbonate.

Prof. Madhava Meegaskumbura from University of Peradeniya, says in a statement, "Only four families of frogs are reported to have ribs, but we show that at least some of Micrixalidae also have ribs, even as tadpoles; this adaptation may provide for greater muscle attachment, helping them wriggle through sand."

The tadpoles are known as fossorial tadpoles for their underground nature. The research give several possible reasons why these behavior may have evolved in the tadpoles. The researchers write in their report, "Rapid fluctuations of surface water in streams during the pre and post-monsoon periods of the Western Ghats, extreme within-stream predator pressure, or the abundance of sub-surface food may each partially account for the fossoriality in this family."

A research paper on the tadpoles can be found here in PLOS One. Here is a video about the unique tadpoles:



Photo: SD Biju