Atlantic Cod (Gadus morhua)

Atlantic Cod, Cod fish (Gadus morhua)
Gerard Soury/Oxford Scientific/Getty Images

The Atlantic cod was called by author Mark Kurlansky, "the fish that changed the world." Certainly, no other fish was as formative in the settlement of the eastern coast of North America, and in forming the booming fishing towns of New England and Canada. Learn more about the biology and history of this fish below.

Atlantic Cod Descriptive Features

Cod are greenish-brown to gray on their sides and back, with a lighter underside. They have a light line that runs along their side, called the lateral line. They have an obvious barbel, or whisker-like projection, from their chin, giving them a catfish-like appearance. They have three dorsal fins and two anal fins, all of which are prominent.

There have been reports of cod that were as long as 6 1/2 feet and as heavy as 211 pounds, although the cod typically caught by fishermen today are much smaller.


  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Actinopterygii
  • Order: Gadiformes
  • Family: Gadidae
  • Genus: Gadus
  • Species: morhua

Cod are related to haddock and Pollock, which also belong to the family Gadidae. According to FishBase, the Gadidae family contains 22 species.

Habitat and Distribution

The Atlantic cod ranges from Greenland to North Carolina.

Atlantic cod prefer waters close to the ocean bottom. They are most commonly found relatively shallow waters less than 500 feet deep.


Cod feed on fish and invertebrates. They are top predators and used to dominate the ecosystem of the North Atlantic Ocean. But overfishing has caused huge changes in this ecosystem, resulting in an expansion of cod prey such as urchins (which have since been overfished), lobsters and shrimp, leading to a "system out of balance."


Female cod are sexually mature at 2-3 years, and spawn in winter and spring, releasing 3-9 million eggs along the ocean bottom. With this reproductive potential, it may seem that cod should be abundant forever, but the eggs are vulnerable to wind, waves and often become prey to other marine species.

Cod may live to over 20 years.

Temperature dictates a young cod's rate of growth, with cod growing more quickly in warmer water. Because of the cod's dependence on a certain range of water temperature for spawning and growth, studies on cod have focused on how cod will respond to global warming.


Cod attracted Europeans to North America for short-term fishing trips and eventually enticed them to stay as fishermen profited from this fish that had flaky white flesh, a high protein content and low fat content. As Europeans explored North America looking for passage to Asia, they discovered an abundance of huge cod and started fishing along the coast of what is now New England, using temporary fishing camps.

Along the rocks of the New England coast, settlers perfected the technique of preserving cod through drying and salting so it could be transported back to Europe and fuel trade and business for the new colonies.

As put by Kurlansky, cod "had lifted New England from a distant colony of starving settlers to an international commercial power."

Fishing for Cod

Traditionally, cod was caught using handlines, with larger vessels sailing out to fishing grounds and then sending men in small dories to drop a line in the water and pull in cod. Eventually, more sophisticated and effective methods, such as gill nets and draggers were used.

Fish processing techniques also expanded. Freezing techniques and filleting machinery eventually led to the development of fish sticks, marketed as a healthy convenience food. Factory ships started catching fish and freezing it out at sea. Overfishing caused cod stocks to collapse in many areas.


Atlantic cod are listed as vulnerable on the IUCN Red List. Despite overfishing, cod are still fished commercially and recreationally. Some stocks, such as the Gulf of Maine stock, are no longer considered overfished.


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Kennedy, Jennifer. "Atlantic Cod (Gadus morhua)." ThoughtCo, Aug. 26, 2020, Kennedy, Jennifer. (2020, August 26). Atlantic Cod (Gadus morhua). Retrieved from Kennedy, Jennifer. "Atlantic Cod (Gadus morhua)." ThoughtCo. (accessed April 1, 2023).