Cod is the common name for the genus Gadus of demersal fishes, belonging to the family Gadidae.[1] Cod is also used as part of the common name for a number of other fish species, and some species suggested to belong to genus Gadus are not called cod (the Alaska pollock).The two most common species of cod are the Atlantic cod (Gadus morhua), which lives in the colder waters and deeper sea regions throughout the North Atlantic, and the Pacific cod (Gadus macrocephalus), found in both eastern and western regions of the northern Pacific. Gadus morhua was named by Linnaeus in 1758. (However, G. morhua callarias, a low-salinity, nonmigratory race restricted to parts of the Baltic, was originally described as Gadus callarias by Linnaeus.)At various times in the past, taxonomists included many species in the genus Gadus. Most of these are now either classified in other genera, or have been recognized as simply forms of one of three species..