The common sole, Dover sole, or black sole is a species of flatfish in the family Soleidae. It is one of the largest fish in the Solea genus. It lives on the sandy or muddy seabed of the northern Atlantic and the Mediterranean Sea where it often semi-immerses itself in the substrate. Dover Sole have a mild, sweet flavor with very firm, small flaked flesh. It is an excellent source of low-fat protein and calcium.