Lungless and luckless frogs

There are several salamaders that are known to be lungless. They rely entirely upon their skin to get their oxygen supply. It is believed that the lunglessness has evolved in their specialized habitat of fast-flowing cold streams. Cold water is able to carry more dissolved oxygen, and also the presence of lungs may put the animal at the risk of being carried away in the current because it would float more easily. Lungless salamanders are found in several parts of North and South America, some parts of Europe and in the Korean peninsula.

In addition to the salamanders, a species of "caecilians" is also lungless. These are worm-like limbless amphibians, living in dark, moist habitats in south america, , some parts of central africa, and south east asia.

However, a recent surprising discovery has been made is of a lungless frog. This is the first frog that has been shown to have no lungs. This Bornean Flat-headed Frog, also called Barbourula kalimantanensis, relies totally on its skin for all its respiration. It was found on an island in Borneo. Though the frog has been reported before, it was extremely rare. The other adaptation that the frog has that it has a lower metabolic rate as well, which reduces its requirement for oxygen. The loss of the lungs also has resulted in a modified anatomical features, like the shifting of the spleen, stomach towards the normal location of the lungs.

As with several other amphibians, this frog is high on the threatened list of amphibians, and likely to be lost in case drastic measures are taken. Here's the entry for the frog in the Red List