Compression was one of the important ways in which fish could change their appearance to fit their surrounding habitat. Pictures One kind of compression among the adaption of fishes is the body compression from one side of the body to the other. Good examples for fish that used this kind of adaption are rays.
Rays live close to the bottom of the ocean.
They also swim pretty close to the ocean floor. Their body shape does perfectly support this way of living because the body is extremely flat. They are pretty well protected by living that way. Predetors are having a hard time finding the ray because he just does not swim in the upper regions of the ocean where most of its enemies have their habitat and also look for food. So one point of the adaption is that the ray goes out of its predators way by moving to the bottom of the ocean where enemies don't appear to often or cannot see the ray very well.