Blink and miss: Kerala’s mystery frog

Aathira Perinchery, Kochi
The Hindu, February 14, 2019

Forget dense forests. Even roadsides could be harbouring new species that are hard to find. Scientists from the University of Delhi have discovered a new amphibian — a mysterious narrow-mouthed frog, that makes only a four-day appearance in seasonal roadside puddles every year in Kerala’s Wayanad district — according to their study published on Wednesday in Scientific Reports.
The frog Mysticellus franki (named after evolutionary biologist Franky Bossuyt from Brussel’s Vrije Universiteit) is not just a new species but also belongs to a completely new genus, Mysticellus (after Latin mysticus, meaning mysterious; and ellus, meaning diminutive, for the frog is just around 3 cm long).
Sonali Garg, a doctoral researcher at the University of Delhi, first found tadpoles of the species — whose physical features and DNA did not match any known species — during routine field surveys in Wayanad district in 2013. After a long search, the team finally found large groups of around 200 adult frogs in 2015 in a single locality in Wayanad, just metres away from vehicular movement, plantation activities and human settlements.
After breeding for four days, the frogs mysteriously disappeared from the spot; a habit that earned the tiny amphibians their name. Back in the laboratory, Ms. Garg and her supervisor S.D. Biju studied multiple aspects of the species — including physical characteristics of adults and larvae, DNA and calls of adult males that they recorded on field — in detail.
Physical features (such as its marble-patterned underside) and DNA studies revealed the frogs to be a completely new species. Adults have two black spots that look like eyes on their backs, a defensive feature.
‘Genetic studies further revealed that the frog is around 40 million years old and its nearest relatives live more than 2,000 km away, in southeast Asia (including Indo-Burma, Malaysia and Vietnam). This southeast Asian connection adds strength to the theories that India and southeast Asia were connected in the past by land bridges, suggest the authors.

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Burrowing frogs add to diversity of Western Ghats

T. Nandakumar, Thiruvananthapuram
The Hindu , June 19, 2017 

Opening another window into the fascinating world of amphibian diversity in the Western Ghats, a research student at the Delhi University has reported the discovery of four new species of burrowing frogs.
The finding, published in the international journal Zootaxa, is the result of five years of extensive explorations in the Western Ghats forests. The four new species belong to the genus Fejervarya, but unlike other members of the family, they possess the ability to burrow.
“Two of the new species could be facing serious threats from human activities,” says Sonali Garg, who conducted this study as part of her PhD research.
“Like most amphibians, they are highly sensitive to changes in the climate, and hence can be studied as environmental indicator species,” says Ms.Garg.
“We need to be concerned about the threats to these frogs and do more studies to re-assess their conservation status,” says Prof. S.D. Biju, who led the study.
The first of the new species, Manoharan’s Burrowing Frog (Fejervarya manoharani), was discovered from the Agasthyamala hills in South Kerala and is named after T.M. Manoharan, former Principal Chief Conservator of Forests, in recognition of his conservation efforts. The Kadar Burrowing Frog (Fejervarya kadar) was collected from the Vazhachal forests and named after the Kadar tribe that was in the forefront of the agitation against the Athiripilly hydel project. The CEPF Burrowing Frog (Fejervarya cepfi) was found in Amboli, a popular hill station in Maharashtra and is named after the Critical Ecosystem Partnership Fund which had contributed to the preservation of biodiversity in the Western Ghats.
Discovered in the Parambikulam tiger reserve, the Neil Cox’s Burrowing Frog (Fejervarya neilcoxi) was named after Dr. Neil Cox of the International Union for Conservation of Nature who was instrumental in preparing the Red List of global amphibian species.

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Western Ghats unveil its amphibian diversity

T. Nandakumar, Thiruvananthapuram
The Hindu, November 17, 2016

Reinforcing the importance of the Western Ghats as a valuable reservoir of amphibian diversity, researchers from the University of Delhi have reported two new species of leaping frogs from Kerala and Karnataka.

The new species - Indirana paramakri and Indirana bhadrai - have been reported in the latest issue of PLOS One, an open access scientific journal published by the Public Library of Science.

The authors, Sonali Garg and S.D. Biju, conducted DNA barcoding of over 200 samples to provide new estimates of the species diversity and distribution of Indirana frogs, an ancient genus endemic to the Western Ghats biodiversity hotspot.

The specimens of Indirana paramakri were collected from wet rocks near streams and under leaf litter in disturbed forest areas in Settukunu and Sugandhagiri, north of the Palakkad Gap in Wayanad district.

The species epithet is derived from the Malayalam words ‘para’ meaning rock and ‘makri’ for frog, referring to the occurrence of the species on rocky terrain. Reddish brown with a black band extending from the nostril to the sides, the species is distinguished by its small snout- vent size and unique toe webbing.

Named after its habitat, Indirana bhadrai is currently known only from the Muthodi forest in the Bhadra Wildlife Sanctuary, located north of the Palakkad Gap in Karnataka. The frogs were found on leaf litter in a secondary forest.

Distinguished by a pointed snout and toe webbing, I. bhadra is light brown with irregular dark brown blotches along the dorsal skin folds and a dark greyish-brown band between the eyes.

According to Dr. Biju, though several studies have been carried out on the Indirana genus, taxonomic ambiguities have remained an impediment for proper identification of species and estimates of diversity and distribution. “Our study provides new distribution records for all the currently known Indirana species.”

The researchers have outlined a distribution trend suggesting genetic isolation between populations of the amphibians found north and south of the Palakad Gap, indicating the role of elevational discontinuities in distribution. They have proposed a reassessment of the IUCN categorisation of all species for effective conservation of these relic frogs.

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Sand-eating tadpoles found in Western Ghats

The Hindu, March 30, 2016 
NEW DELHI,  

Adding to the burgeoning cache of frog-finds in India, researchers have discovered a sand-eating tadpole that lives in total darkness, until it fully develops into a young frog.

S.D. Biju from the University of Delhi said in a statement: “We provide the first confirmed report of the tadpoles of Indian Dancing frog family. These tadpoles probably remained unnoticed all these years because of their fossorial [underground] nature, which in itself is a rare occurrence in the amphibian world.”

The group of scientists from the University of Delhi, the University of Peradeniya, Sri Lanka and Gettysburg College, California discovered and documented the tadpole in the peer-reviewed PLOS One, an open-access journal.

The tadpole belongs to the so-called Indian Dancing Frog family, Micrixalidae. They get that name from their habit of waving their legs as a sign of territorial and sexual display while sitting on boulders in streams.

Though these kind of displays are well known, information on the tadpoles of these frogs were completely unknown, according to Dr. Biju.

In January, Dr. Biju reported in the same journal of a frog species called Frankixalus jerdonii, once considered a species lost to science.

Skin-covered eyes

The purple tadpoles were discovered from the deep recesses of streambeds in the Western Ghats and they possess muscular eel-like bodies and skin-covered eyes, which helps them to burrow through gravel beds.

Though they lack teeth, they have serrated jaw sheaths, to possibly prevent large sand grains from entering the mouth while feeding and moving through sand.

The authors posit that unlike most tadpoles that swim early on, the Micrixalidae tadpoles hang onto underwater rocks with their powerful suckering mouths. When their arms grow strong enough they dig underground, where they live most of their lives, only to emerge in forest streams to reproduce.

Other unusual features of the tadpoles were ribs and whitish globular sacs storing calcium carbonate, known as “lime sacs,” noted Madhava Meegaskumbura from the University of Peradeniya.

“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,” he said.

 

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