The cod belongs to the Gadidae group and its young are commonly called codling. Its body is elongated and streamlined with a relatively large head and protruding upper jaw. It is easily recognisable due to the bright line on its side which extends from mouth to tail. It is a light grey colour with small spots, a white belly and a single barbel on the lower jaw.
The cod can reach a size of up to one metre and a maximum weight of 40 kilograms, although specimens still living in the Baltic Sea are usually much smaller than their counterparts living elsewhere. On average, the cod reaches a weight of 2.5 kilograms and a length of 60 centimetres.
Cod prey on crabs, small fish, as well as rock worms and annelid. Due to their feeding habits, young are usually found in shallow areas or close to the shore. Cod only reach sexual maturity after 6 to 15 years. Their spawning season is in spring and a pregnant female can lay 500.000 to 5 million eggs.
Cod is known to react strongly to environmental influences.