Characteristics
Cods of the genus Gadus have three rounded dorsal and two anal fins. The pelvic fins are small, with the first ray extended, and are set under the gill cover (i.e. the throat region), in front of the pectoral fins. The upper jaw extends over the lower jaw, which has a well-developed chin barbel. The eyes are medium sized, approximately the same as the length of the chin barbel. Cod have a distinct white lateral line running from the gill slit above the pectoral fin, to the base of the caudal or tail fin. The back tends to be a greenish to sandy brown, and shows extensive mottling, especially towards the lighter sides and white belly. Dark brown colouration of the back and sides is not uncommon, especially for individuals that have resided in rocky inshore regions.
The Atlantic cod can change colour at certain water depths. It has two distinct colour phases: gray-green and reddish brown. Its average weight is 5–12 kilograms (11–26 lb), but specimens weighing up to 100 kilograms (220 lb) have been recorded. Pacific cod are smaller than their Atlantic cod and are darker in colour.
Read more about this topic: Cod