The name cod refers to two separate species of fish; Atlantic cod and Pacific cod that inhabit different oceans. When you purchase cod in 2011, it is almost certainly Pacific cod, due to its sufficient numbers in the wild. Buy or eat black cod and you are enjoying sablefish, which resembles the cod, but comes from a different family.
Range and Habitat
Atlantic cod, or Gadus morhua, is a deep water fish, living at depths of 1,300 feet or more, according to the Monterey Bay Aquarium. Atlantic cod live on both sides of the Atlantic ocean in cold water. They are part of the groundfish species that live on the ocean floor. Pacific cod, or Gadus macrocephalus, are cold water fish found in the northern parts of the Pacific Ocean near Japan, Alaska and Canada. They inhabit the bottom of the ocean, although they stay in the shallower parts of the ocean. Sablefish, called black cod and butterfish, or anoplopoma fimbria, inhabit the waters of the Pacific Ocean from Alaska to British Columbia and can be found off the coasts of California, Oregon and Washington.
According to the "Encyclopedia Britannica," Atlantic cod have three dorsal fins, two anal fins and a chin barbel, or appendage. Colors range from green, gray, brown to black. They normally weigh 25 pounds at capture but can grow up to 6 feet and weigh 200 pounds. Pacific cod are brown or grayish with dark spots or patterns on their side. They also have a chin barbel along with dark fins with white edges. Sablefish resemble cod which explains the name black cod but they are not part of the cod family.
Both Pacific cod and sablefish have been managed well and not overfished. Both are plentiful off the Pacific waters of Alaska and Canada. The Seafood Watch at Monterey rates sablefish caught off Alaska and British Columbia as a best choice for consumers. It also gives best choice to Pacific cod caught off the United States. Atlantic cod has been overfished, especially off the coasts of the United States and Canada. Fishing is limited so the stock can be replenished. Monterey recommends avoiding the fish unless caught near Iceland, the northeast Arctic or the Gulf of Maine.
Atlantic cod are know by varying names including cod and codling. A small Atlantic cod can be called a scrod cod while larger are markets and steakers. Pacific cod can be recognized by the names cod, Alaska cod, gray cod, true cod and treska. Sablefish, beside the names black cod and butterfish, are called skil, beshow and coalfish. When served as sushi, its name is gindara.