Dicologlossa cuneata. The céteau, or wedge sole, is a flat bottom-dweller, smaller than other soles. They are caught mostly at night from June to September off the coast of La Cotinière in the Charente-Maritime, where the fish is also known as the langue d’avocat (‘lawyer’s tongue’)!
More widely known in Spain than France, it tastes similar to sole.
Image by Myrabella