European flounder the males when they measure and the females when they measure . The European flounder sometimes hybridises with European plaice ("Pleuronectes platessa") and, particularly in the western Baltic Sea, the hybrid is common. The European flounder is used for human consumption but is not so highly esteemed as the European plaice or common sole ("Solea solea"). The most important fisheries are in the Baltic Sea and the waters around the Netherlands and Denmark. In 2010, the total world catch was about nineteen thousand tonnes, mostly caught by bottom trawling. The fish is marketed fresh and frozen and can be fried,
Flatfish …bony fish as a rule have a marked tendency to be flattened in a vertical direction…. It was natural, therefore, that when the ancestors of [flatfish] took to the sea bottom, they should have lain on one "side"…. But this raised the problem that one eye was always looking down into the sand and was effectively useless. In evolution this problem was solved by the lower eye ‘moving’ round to the upper side. Flatfish is considered a Whitefish because of the high concentration of oils within its liver. Its lean flesh makes for a unique flavor that differs from species