Scientists have discovered seven new frog species, four of which are about the size of an M&M. The frogs, which are small enough to sit on a child’s thumbnail, was discovered in Western Ghats of India after 5 years of extensive exploration. These nocturnal amphibians measure between 12.2mm and 15.4mm.
All the new species belong to the genus Nyctibatrachus, scientists said. Frogs of this genus are commonly known as night frogs because of their dark colors and habitats.
The discovery makes the rich but eco-sensitive Ghats the second-largest global amphibian hotspot after Brazil’s Atlantic Forest, a research paper reported on Tuesday.
The study conducted by Delhi University-based researchers SD Biju and his team in the Western Ghats said that these frogs were overlooked earlier because of their insect-like calls and secretive habitats.
Named after the place of discovery such as Sabarimala and Athirappilly in Kerala, the paper said they were found inside “damp tree leaf litter or marsh vegetation” — unlike night frogs that predominantly reside along streams.
“The miniature species are locally abundant and fairly common, but they have probably been overlooked because of their extremely small size, secretive habits and insect-like calls,” said Delhi University research scholar Sonali Garg, the paper’s lead author.
“It is a very interesting finding because they are from small geographical region. Apart from big animals like Tiger and elephants, there is a need to conserve this tiny amphibian also as they have been ignored. It is a very cute and small animal,” Prof SD Biju, who led the new study, told PTI.
“Over 32 per cent, that is one-third of the Western Ghats frogs are already threatened with extinction. Out of the seven new species, five are facing considerable anthropogenic threats and require immediate conservation prioritization,” he said, adding that these frogs are active during both night and day time unlike other breeds that are active only during night.
The first of the new discoveries was sighted in 2012, but differentiating their genre using DNA sampling and analyzing their unique calls took time, he said.
The study, titled “Seven new species of Night Frogs from the Western Ghats Biodiversity Hotspot of India, with remarkably high diversity of diminutive forms”, was published yesterday in PeerJ, a peer-reviewed open access journal.
In the lab, the newly sampled frogs were confirmed as new species by using an integrated taxonomic approach that included DNA studies, detailed morphological comparisons and bioacoustics. Evidence from these multiple sources confirmed that the diversity of Night frogs is higher than previously known and particularly remarkably for the miniaturized forms.
The paper stressed that more studies were required to understand the “evolutionary advantages of miniaturization and adaptation to terrestrial life” within the Nyctibatrachidae family, comprising largely robust torrential frogs.
Previously, the Night Frog genus comprised of 28 recognized species of which only three were miniature-sized (<18mm) Now the total number of known Nyctibatrachus species has increased to 35, of which 20% are diminutive in size. This frog genus is endemic to the Western Ghats of India and represents an ancient group of frogs that diversified on the Indian landmass approximately 70-80 million years ago.
“Once the extinction risk is assessed and we can better understand the realities of each species, this would allow for the tailoring of both research and conservation actions accordingly,” said Ariadne Angulo, co-chair of a specialist group on amphibians at UN’s wildlife monitoring authority, International Union for Conservation of Nature (IUCN).