The fish lives in the sea a while, and then develops rudimentary lungs and comes to live along the shore lines.

Some freshwater species and almost all terrestric species have developed lungs.

They also developed primitive lungs, as did some lobe-finned fish.

Most breathe with gills, although certain land crabs have developed lungs.

As the tadpoles grow, they develop lungs and gain the ability to breathe air.

Not until a frog develops lungs does it leave the water and live on the land.

And over time's long course, some of them develop lungs.

They had started to develop lungs, but still breathed predominantly with gills.

In the adult stage, amphibians (especially frogs) lose their gills and develop lungs.

The first of our ancestors to develop lungs almost certainly lived in water.