Two froggy sisters make news
The Kandyan Dwarf Toad, dubbed the world’s rarest toad, has become a more select amphibian with the discovery that it shares its genus with only one other species, not two as previously thought. The toad, a member of the Adenomus genus, was discovered and last seen in the 1870s and had been thought to be extinct until it was found again in 2009.
Naturalists believed there were three species in the genus but now say DNA analysis reveals that one of them, Dasi’s Dwarf Toad (Adenomus dasi) is, in fact, the Kandyan Dwarf Toad “in disguise”. The other species is Adenomus kelaartii (Kelaart's toad).
One factor that led to the error in identification is that Adenomus kandianus has fully webbed toes while Adenomus dasi has partially webbed feet.
“When amphibian specialists Kelum ManamendraArachchie and Rohan Pethiyagoda were describing Adenomus dasi in 1998 they were actually describing a slightly different mutate of A. kandianus as they had access to only a few specimens,” said lead researcher Dr. Madhava Meegaskumbura of the Faculty of
Science at
the University of Peradeniya. “In a paper published last week, we put it right in the spirit of science, testing the species using many different criteria.”
Mr. Pethiyagoda and Mr. Manamendra-Arachchi are co-authors of the new research paper, published in the prestigious international journal Zootaxa.
“They contributed with their previous data and knowledge, did additional measurements and contributed to the writing, making this a collective effort and a better story,” Dr. Meegaskumbura said.
“My graduate students, Gayani Seneviratne, Nayana Wijayatilleke, Beneeta Jayawardene and Champika Bandara also contributed greatly, enabling us to use many different criteria such as DNA, morphology, tadpoles, ecology, vocalisations and bone comparison to ascertain the species boundaries of these toads.”
Dr. Meegaskumbura said the research team had been glad to find a large population of hundreds of these toads at one location; the toads, endemic to Sri Lanka, are on the critically-endangered wildlife list.
Sri Lanka is home to 119 amphibians with as many as 102 of them being endemic, making this country one of the hottest hotspots for amphibian diversity in the world.
There are eight species of toads in Sri Lanka, belonging to two genera called Adenomus and Duttaphrynus, and six of them are endemic to the country.