The European flounder (Platichthys flesus) is a flatfish of European coastal waters from the White Sea in the north to the Mediterranean and the Black Sea in the south. It has been introduced into the United States and Canada accidentally through transport in ballast water. It is caught and used for human consumption.

Platichthys flesus (L.), family Pleuronectidae, is one of the most common of the flatfish species found in European waters; known throughout Britain as ‘fluke’, ‘butt’ or more commonly as the ‘European flounder’ (Fig. 1).

Platichthys flesus (Linnaeus, 1758) Common name: European flounder Taxonomy: available through Identification: Wheeler (1969); Maitland (1977); Wheeler (1978). Size: 50 cm. Native Range: Marine; can penetrate freshwater. This species is native to the northeast Atlantic Ocean, Mediterranean Sea, and the Black Sea (Robins et al. 1991b).