What Is A Cod?

Cod is a fish that lives in cold and deep ocean waters like the Arctic Ocean.  This fish has been a staple of the European diet for centuries and is still consumed in large quantities particularly in England and Portugal.  British diets include quite a lot of fresh cod, often deep-fried and served as fish and chips, and the Portuguese enjoy their cod salted.  Cod is highly susceptible to overfishing, loss or threat to environment, and like many other large fish high levels of mercury bioaccumulation.

Cod can grow up to 30 kgs (66 lbs) and can live to be up to 15 years old.  Often distinguished by their whiskers or barbells, cod appear to wear a large downturned moustache.  They have a protruding lower jaw and a blunt head shape that make them resemble a bulldog.  Most cod are bottom dwellers and feed on small crustaceans and other fish.  They rarely reach their top weight, but are nonetheless large fish.  Cod reach sexual maturity around the age of 6 when they will start breeding.

Cod has white, dense flesh and is not an oily fish.  This makes it ideal for salting because it can be split, salted, and dried with no concern of it going rancid or rotting.  Any food that can be this easily preserved has traditionally been very popular and useful.  Salted cod is very hard and can be stacked and shipped long distances.  The United States made a large profit on preserved cod when it was a British colony.  

Salted cod is called bacalhau in Portugal where it is used in many popular traditional dishes.  Salt cod will usually be soaked before it is used to soften it and remove excess salt. The Basque people had a strong cod based economy whereby they traded salted cod for more salt with which they would salt their next catch.  Scandinavian people are known for diets high in fish and they enjoy salt cod as an alternative to the oily herring in many of their popular dishes.

Cod conservation means that cod is less often used in English fish and chips lately.  Although it has long been the traditional fish to use, Atlantic cod is officially considered a threatened species by marine biologists who encourage a severe reduction on commercial fishing. Northern Pacific cod, ling cod, is still commercially fished and known to reach impressive sizes.  These too are in danger of being overfished and marine conservationists are trying to save them before they disappear entirely.

It is a fish commonly used for food where I live. It is low in fat content and has a mild flavor. The cod's liver is processed to make cod liver oil for vitamin a and d , and omega 3 fatty acids.

It is like a shell(outer cover),or a husk(the thin dry cover of different fruits,)with seeds inside.    
The word cod can also be associated with fish(cod-fish) and the oils that are taken from this fish,
to make cod-liver-oil