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,
Hypselodoris kanga white. The inner edge of each gill is reddish orange in the upper quarter, deep blue in the mid region and white in the basal quarter. The smooth outer side of each gill is orange-red in the upper quarter and the rest has a background colour of light blue with a row of large yellow spots. The two outer corners of each gill are bordered with red at the tip becoming dark blue at the base. This species can reach a total length of at least 70 mm and has been observed feeding on yellow sponges from the genus "Dysidea".