Gadus morhua

The Atlantic cod (pl.: cod; Gadus morhua) is a fish of the family Gadidae, widely consumed by humans. It is also commercially known as cod or codling. In the western Atlantic Ocean, cod has a distribution north of Cape Hatteras, North Carolina, and around both coasts of Greenland and the Labrador Sea; in the eastern Atlantic, it is found from the Bay of Biscay north to the Arctic Ocean, including the Baltic Sea, the North Sea, Sea of the Hebrides, areas around Iceland and the Barents Sea. Atlantic cod can live for up to 25 years and typically grow up to 100–140 cm (40–55 in), but individuals in excess of 180 cm (70 in) and 50 kg (110 lb) have been caught. They will attain sexual maturity between ages 2 and 8, but this varies between populations and has varied over time. Colouring is brown or green, with spots on the dorsal side, shading to silver ventrally. A stripe along its lateral line...

The diet of the Atlantic cod consists of fish such as herring, capelin (in the Eastern Atlantic Ocean), and sand eels, as well as squid, mussels, clams, tunicates, comb jellies, brittle stars, sand dollars, sea cucumbers, crustaceans, and polychaetes. Stomach sampling studies have discovered that small Atlantic cod feed primarily on crustaceans, while large Atlantic cod feed primarily on fish. In certain regions, the main food source is decapods with fish as a complementary food item in the diet. Wild Atlantic cod throughout the North Sea depend, to a large extent, on commercial fish species also used in fisheries, such as Atlantic mackerel, haddock, whiting, Atlantic herring, European plaice, and common sole, making fishery manipulation of cod significantly easier. Ultimately, food selection by cod is affected by the food item size relative to their own size. However, providing for size, cod do exhibit food preference and are not simply driven by availability. Atlantic cod practice some cannibalism. In the southern North Sea, 1–2% (by weight) of stomach contents for cod larger than 10 cm (4 in) consisted of juvenile cod. In the northern North Sea, cannibalism was higher, at 10%. Other reports of cannibalism have estimated as high as 56% of the diet consists of juvenile cod. When hatched, cod larvae are altricial, entirely dependent on a yolk sac for sustenance until mouth opening at ~24 degree days. The stomach generally develops at around 240 degree days. Before this point the intestine is the main point of food digestion using pancreatic enzymes such as trypsin.

Life expectancy about 25 years.

Atlantic cod will attain sexual maturity between ages 2 and 8, but this varies between different populations and has also varied over time with a population. Their gonads take several months to develop and most populations will spawn from January to May. For many populations, the spawning grounds are located in a different area from the feeding grounds so require the fish to migrate in order to spawn. On the spawning area, males and females will form large schools. Based on behavioral observations of cod, the cod mating system has been likened to a lekking system, which is characterized by males aggregating and establishing dominance hierarchies, at which point females may visit and choose a spawning partner based on status and sexual characteristics. Evidence suggests male sound production and other sexually selected characteristics allow female cod to actively choose a spawning partner. Males also exhibit aggressive interactions for access to females. Atlantic cod are batch spawners, in which females will spawn approximately 5–20 batches of eggs over a period of time with 2–4 days between the release of each batch. Each female will spawn between 2 hundred thousand and 15 million eggs, with larger females spawning more eggs. Females release gametes in a ventral mount, and males then fertilize the released eggs. The eggs and newly hatched larvae float freely in the water and will drift with the current, with some populations relying upon the current to transport the larvae to nursery areas.

The Atlantic cod is one of three cod species in the genus Gadus along with Pacific cod and Alaska pollock. A variety of fish species are colloquially known as cod, but they are not all classified within the Gadus, though some are in the Atlantic cod family, Gadidae.

The Atlantic cod is one of three cod species in the genus Gadus along with Pacific cod and Alaska pollock. A variety of fish species are colloquially known as cod, but they are not all classified within the Gadus, though some are in the Atlantic cod family, Gadidae.