The whiting Merlangius merlangus is a cod-like fish. It has an elongated body with a small head and a pointed snout. It can grow up to 70 cm in length. It has a blue-green upper colouring and is silvery-white underneath. It has three dorsal fins and two anal fins. The pectoral fins are on the side and the pelvic fins are near the gills. The tail is truncate. Its upper jaw projects above the lower jaw. A small dark spot is found at the base of the pectoral fins and the lateral line is brown in colour.It can be differentiated from similar species such as the haddock, Melanogrammus aeglefinus, by a small dark spot which is found at the base of the pectoral fins and by the lateral line being brown and not black. It is very similar to the blue whiting, Micromesistius poutassou, but can be distinguished by the dorsal fins being close together.