Atlantic Cod: Origin and Evolution

The Atlantic cod is one of the best-known fishes of the world. Atlantic cod and its relatives are distinguished by the presence of three dorsal fins on the back, two anal fins on the lower side and anteriorly located pelvic fins positioned slightly in front of the pectorals. Atlantic cod adapted to occupy most all of the continental shelves that circumscribe the North Atlantic boreal region. The modern gadoids are among the few fishes endemic to the continental shelves of the North Atlantic. The North Atlantic is a young ocean relative to the Pacific and Indian Oceans. Gadoid evolution in the North Atlantic filled many habitats and ecological niches. Few marine species have received as much attention from population geneticists as the Atlantic cod. The Atlantic cod is an endemic species of the North Atlantic that inhabits all of its continental shelves, and in many of these regions has become the dominant large fish predator.