Flatfish and Flat fish

Flatfish noun - Any of several families of fishes having flattened bodies that swim along the sea floor on one side of the body with both eyes on the upper side.

Flat fish and flatfish are semantically related. In some cases you can replace phrase "Flat fish" with "Flatfish", this terms are similar.

Flatfish and flat fish are semantically related. You can use "Flatfish" instead a noun phrase "Flat fish".