The lungless frog found on the island of Borneo, in Indonesia, does not have lungs. He breathes from his skin and is called Barbourula kalimantanensis (the frog without lungs). They are found in cold-water streams, and this species was accidently discovered.
Scientists feel that this adaptation helps them to adjust to the higher oxygen content found in cold water. The metabolic rate of frogs is low, and this means they need less oxygen. So breathing through their skin allows them to control their oxygen intake.
This species is very rare and endangered, and so scientists do not know much about their physiology because they cannot dissect too many of them for research.
Their bodies are flatter than other frogs and this increases the surface area of their skin.