Scientists find first lungless frog
Posted by Miqe on April 7, 2008
Researchers working in Borneo have discovered the only known frog with no lungs, the team reported Monday.
National University of Singapore biologist David Bickford, the lead researcher, said in a release that the frog, Barbourula kalimantanensis, has an “amazing ability to breathe entirely through its skin.”
The tiny frog, measuring less than 40 mm and weighing 6.5 grams, was found in western Kalimantan, Indonesia, in August by researchers employing new search methods.
It lives in cold, rushing water and is so rare that the only previous evidence of the species was reported 30 years ago.
The researchers said the frog receives all necessary oxygen through its skin. Among four-legged creatures, only amphibians are known to breathe without lungs — previously only in two families of salamanders and a species of caecillian, a limbless amphibian.
Bickford said it was a “shock” to discover that the species did not have lungs.
“When we did [find the frog] and I was doing the initial dissections — right there in the field — I have to say that I was very skeptical at first,” Bickford said in a release. “It just did not seem possible. We were all shocked when it turned out to be true.”
The researchers hypothesized that the frog may have evolved without lungs, or lost its lungs, in adaptation to the high-oxygen environment of its habitat and the species’ preference to sink, rather than float, which would have been hindered by lungs full of oxygen.
They noted that deforestation and illegal gold mining in the area is threatening both the species and further research into its reproduction, feeding and life. Further studies “may be hampered by the species’ rarity and endangerment. We strongly encourage conservation of remaining habitats of this species,” they said.
The researchers said they tried to be as non-invasive as possible, dissecting only four specimens completely and four partially to confirm the lack of lungs.
The findings are published in the April 8 edition of the journal Current Biology.