DAB (Limanda limanda), a species of flat-fish belonging to the family Pleuronectidae and distinguishable from plaice and flounder by the distinct arch in the lateral line at the anterior end. It is of a brown or ashen grey colour with irregular dark markings and close set scales, and is to be found on sandy shores in the north of Europe, the length attained being 12 in. Another species is the sand dab or rusty dab (L. ferruginea) found on the coasts of North America. See also FLAT-FISH.