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.
