What is the difference between the skeleton of amphibians and the skeleton of fish, and how

What is the difference between the skeleton of amphibians and the skeleton of fish, and how can these differences be explained?

Fish only live in water and only swim. This means that they do not have legs in the skeleton, like amphibians. After all, they don’t need to walk on the firmament. There are neither anterior nor posterior ones in the fish skeleton. The skeleton of a fish is flat or streamlined, like a torpedo. For the convenience of the fish, cut the water column so that there is less resistance from the water when moving in it. Amphibians, on the other hand, do not have such a skeleton. After all, they cannot swim their whole life in water, they come out on land and live here longer.