When youbecome a terrestrial animal, you have to have eyelids that cankeep the cornea and other parts of the eye moist. The larval forms have a spiracle - a little trapped gill slitthat opens up on the side of the head. And the larval forms have external gills - these gills are notyour usual fish gills. These are a new evolutionary development. All of these features are converted into corresponding adultfeatures or lost.
Weak limbs become a little bit stronger.
They lose the spiracle. And they lose their externalgills. Some species of salamanders as adults are still aquatic animals. Some of them are very strongly aquatic and virtually never getout on land. And there are some adult salamanders that canactually spend a significant fraction of their life in water anda small fraction of it on land.