Flounder Headed and Headless mainly differ in flavor and texture, but not much else.

About Flounder:

Flounders, also known as flounders inhabit shallow, sandy bottoms and prey on small fish and shrimp. They are particularly well adapted to a bottom-dwelling life on the seabed. Due to their flattened body. The eyes are the same on the upward-facing side of the body, and the color of this side works well with their surroundings; the downward-facing side of their body is white. Flounder have extremely fine scales on the surface of their body. Flounder have only one dorsal fin, which extends from the head almost to the caudal fin. They live mainly in temperate waters and are an economically important fish in temperate seas. The "iron dried" commonly used in the Chaoshan area for wrapping dumplings is actually dried flounder, which is made from dried flounder.