They are tiny, they are tough, and the latest of their ilk to be identified has been named after Kerala.
Tardigrades are so small you need high-end microscopes to study them. Commonly called ‘water bears’ and ‘moss piglets’, they also rank among the hardiest animals on planet earth despite their minuscule size. Researchers have now come across a new tardigrade species of the genus Stygarctus, which they have named after the State of Kerala where it was found.
Stygarctus keralensis - the new species - is the first taxonomically described marine tardigrade from the Indian waters, which makes the discovery a significant one, the researchers say.
Stygarctus keralensis was discovered from Vadakara in north Kerala by a research team which consisted of Vishnudattan N.K., Jayachandran P.R., and S. Bijoy Nandan, professor, Department of Marine Biology, Microbiology and Biochemistry, Cochin University of Science and Technology. J.G. Hansen, University of Copenhagen, was associated with the study. Their findings have been published in Zootaxa.
Stygarctus keralensis is the eighth species named under the genus Stygarctus, which grows up to a length of 130 micrometres (0.13 mm). “Tardigrades are very tough animals and are found everywhere on earth, from mountain tops to deep sea. They have survived five mass extinctions. They are also related to insects, spiders, and crustaceans and are the lesser known taxa of invertebrates,” says Dr. Bijoy Nandan.
Tardigrades employ a curious process to deal with environmental stress. Called ‘cryptobiosis’, it brings their metabolic activities to a reversible standstill. A death-like state, more or less. Certain tardigrade species can withstand extreme temperatures, pressures, radiation, and dehydration.
The present discovery is an outcome of an ongoing Ministry of Earth Sciences-National Centre for Earth Science Studies study on the ecology and diversity of submarine groundwater habitats of Kerala. Globally, scientific interest in tardigrades has grown, but in India it is still in the nascent stages, says Dr. Bijoy Nandan. There is a need for further explorations on tardigrade-meiofauna from India, he says.
