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,
Oily fish Oily fish Oily fish have oil in their tissues and in the belly cavity around the gut. Their fillets contain up to 30% oil, although this figure varies both within and between species. Examples include small forage fish, such as sardines, herring and anchovies, and other larger pelagic fish, such as salmon, trout, tuna, swordfish and mackerel. Oily fish can be contrasted with white fish, which contain oil only in the liver, and much less overall than oily fish. Examples of white fish are cod, haddock and flatfish. White fish are usually demersal fish which live on or near the