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  The black cod is also known as the sablefish, small-scaled cod and the butterfish. This saltwater fish is found in the deep waters of the Antarctic Sea and North Pacific Ocean. Black cod fish are silver, yellow and even reddish-brown in color, with fin-rays, a forked tail and very small scales. These fish are highly adaptable to extreme cold temperatures, and grow up to 2 ½ feet in length.
  
  Most of the black cod we eat is caught by commercial fishermen off the coast of Alaska, Oregon, Washington or northern California. The black cod population is managed by fishing quotas to prevent overfishing and maintain a stable number. Black cod is one of the most desirable fish served in restaurants, providing diners with a healthy serving of high-quality protein and omega-3 fatty acids. Black cod fish have a delicate, but firm texture, and flavorful, buttery rich flesh. This combination of texture and flavor enables chefs to prepare, cook and serve this fish by a variety of methods. When black cod is not available, substitute another firm-textured fish.
  
  

Hake

• Like the black cod, hake have silver or reddish-colored skin. The silver hake are often referred to as "whiting," and the red hake are called "ling" or "squirrel" hake. Hake produce great fillets, but unlike the black cod, their flesh can vary from soft to firm in texture. Hake are lean with very few bones and are easy to prepare. Fresh hake have a firmer texture and saltwater scent, making them a viable alternate for the black cod.
  
  

Salmon

• Salmon may be substituted for black cod, as this fish is also widely recognized for its thick flavorful meat, and is a substantial source of high-quality protein and healthy fatty acids. The black cod, however, trumps the salmon with a higher content of omega-3 fatty acids. As a rule of thumb, Atlantic salmon are most often farm-raised fish, while Pacific salmon are fished from the Pacific Ocean.
  
  

Chilean Sea Bass

• The Chilean sea bass has a thick sweet fillet, similar in flavor and texture to the black cod. This fish is a reasonable substitute, although it tends to be higher in price. The Chilean sea bass is often referred to as the Patagonian toothfish. It has been exploited and has been the center of controversial illegal fishing and poaching. Aquaculture nurseries and Australia are the primary source for legal healthy Chilean sea bass.