Frog without Lungs!
Wow, here’s a frog without lungs, how does he breathe?
Lunglessness is extremely rare in amphibians because, although the animals breathe through their skin, the method delivers only a fraction of the oxygen provided by lungs. It is only practical for cold-blooded animals, which use far less energy than mammals.
One family of salamanders and one species of caecilians are the only other lungless amphibians. There are no known lungless reptiles.
Bickford and his colleagues think that air-filled lungs may have made it difficult for Barbourula’s ancestors to sink to the riverbed through fast-flowing water, so it evolved towards a lungless existence.
The clear, cold, fast-flowing streams they live in made this change possible. In the same way cold carbonated drinks hold more “fizz”, cold water can hold more dissolved oxygen. And the rapidly flowing streams send a plentiful supply of the oxygen-rich water over the frog’s body.
via newscientist
Tags: amphibians, ancestors, bickford, carbonated drinks, cold blooded animals, cold water, colleagues, existence, flowing streams, flowing water, fraction, frog, lungs, mammals, oxygen, plentiful supply, reptiles, rich water, riverbed, salamanders
Loading ...