Better question: why are there evolutionary niches allowing flat fish to thrive? Three answers, although you shouldn't consider me an authority:
1. Flounders lay flat on the bottom, and flatness allows them to be less conspicuous.
2. Flatness minimizes shadows on the ocean floor, thus aiding in stealth.
3. In coral reefs, a flat body and a long nose allows fish to get at food inside coral heads.
In each of these three scenarios, it's not hard to understand how flatter fish would be more successful -- and therefore more likely to reproduce.
a fish that lives in a flat
Flounder is a word for a flat fish.
Yes, a Flounder is a flat fish. If you mean Flounder from 'The Little Mermaid', the yellow sand blue fish, then no, he is not flat. (Although he is not 3D)
Types of flat
flat fish
Snapper are flat fish that are orange and white. They are the same as in Finding Nemo.
flat fish
If you google "flat fish" you will see that there are more than 500 species of "flat fish" listed. If you google "round fish" you will see that there are even more fish that are round in section than there are flat fish. I guess that means that there is not enough room here to list them all, even if I did know all their names.
flat head (fish)
They can eat little fish.
different kinds of flat fish
Flounder and Sole.