Bornean Flat-headed Frog

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Kingdom:	Animalia
Phylum:	Chordata
Class:	Amphibia
Order:	Anura
Family:	Bombinatoridae
Genus:	Barbourula
Species:	B. kalimantanensis

Binomial name

Barbourula kalimantanensis
Iskandar, 1978

The Bornean Flat-headed Frog (Barbourula kalimantanensis) is a species of toad in the Bombinatoridae family. It is notable as the only frog known to have no lungs, although lungless species have also evolved in the two other amphibian orders caecilians (Atretochoana eiselti) and salamanders (family Plethodontidae and genus Onychodactylus).

The frog, no more than 70 mm (2.8 in) long, lives in cold, clear, and fast rivers in remote areas of the rainforests of Kalimantan, the Indonesian part of the island of Borneo. Its natural habitats are rivers in tropical moist lowland forests. It is threatened by habitat loss from severe degradation of the river habitats by increased turbity and toxic metals used in mining and other unfortunate consequences of development on the island.

Djoko Iskandar, an Indonesian zoologist, first described the Bornean Flat-headed Frog.^[1] However, he did not know the frog was lungless until Bickford et al. cut eight of the specimens open in the lab. It has the rare characteristic of being an amphibian without lungs, and instead breathes entirely through its skin. Instead, other internal organs (the stomach, spleen and the liver) take up the space which normally would be filled by the lungs. By retaining the lunglessness of their tadpole stage, the frogs are much flatter than typical frogs, which might help absorb oxygen and avoid being swept away in fast streams.^[2]

[edit] References

^ Iskandar, Djoko T. (1978). "A New Species of Barbourula: First Record of a Discoglossid Anuran in Borneo". Copeia 1978 (4): 564–566.
^ Bickford, David; Iskandar, Djoko; Barlian, Anggraini (2008). "A lungless frog discovered on Borneo". Current Biology 18 (9): R374–R375. doi:10.1016/j.cub.2008.03.010.