They usually do not exceed 30 kg, but there is one record of a cod that weighed about 96 kg and was more than 180 cm long. Atlantic cod grow at different rates in different areas. There are annual differences in growth rate in the same area depending upon population sizes, temperature, and food. Generally, growth is slower off Labrador and eastern Newfoundland than on the southern Grand Banks and is slower in the Gulf of St. Lawrence than on the Scotian Banks and Georges Bank. Most of the cod caught by fishermen in Atlantic Canada are from four to eight years old.
Juveniles feed mainly on shrimp, amphipods, euphausiids, and fish and shellfish larvae.
Adult cod feed mainly on capelin, herring, sand launce, flounders, young Greenland turbot, crabs, shrimp, brittle stars, combjellies, and a host of other species of fish and shellfish. In fact, a cod will eat almost anything including stones so that it can digest the sea anemones, hydroids, and other organisms growing on them. The size at first maturity generally ranges from about 45 to 60 cm in length. The males generally mature at a slightly younger age and smaller size than the females. C od spawning occurs over a wide area of the continental shelf and over a wide range of bottom depths.