The cod family looks like typical fish. They have no pointed fins, are covered in small round scales, and most fish have a whisker growing under their jaws. There is a wide range of sizes in the cod family, with the smallest silver slate fish measuring only 11 centimeters to 15 centimeters in length, while the largest fish of the same species can reach up to 180 centimeters in length. However, you don't see cod this big on store counters anymore because fishermen don't allow them to grow this big. The cod are caught before they are even young.

There are 53 known species of cod. Their hereditary territory is undoubtedly the cold waters of the northern hemisphere, where there are 48 species. There is also a freshwater river cod that is also a Northern Hemisphere animal, inhabiting freshwater bodies in the northern regions of Asia and Europe and the Americas. The remaining four species find their habitat in the cold waters of the Southern Hemisphere. Most of all cods prefer cold water, and only a few are adapted to cooler waters, including 2 species of cods from the Baltic and Black Seas, and 16 species of cods from the Mediterranean Sea. The ones that like cold water the most are the polar cod, haddock and small cod. They frequent the Arctic Ocean. Cod and two species of cod settle in the Arctic Ocean. Cods are not found in tropical waters.

While it is difficult to identify cod as demersal based on their feeding characteristics, they are still demersal. The smallest of them, cod, hake and blue whiting, feed on small plankton, that is to say, they eat small and very small plants and animals: cod and pollock feed on large krill as adolescents. Adult polar cod and northern cod are wild and hunt large game, mainly fish. The rest of the cod family, which includes haddock, haddock, albacore, and river cod, feed on organisms under the water. They live in areas where marine diets are quite abundant and are able to accumulate fat in large quantities, but they do not store it in muscles and body cavities as many other fish do. Cods concentrate all the fat they accumulate in their liver, and a fish without fat that is a real delicacy.

Cods have a very low reproductive rate. Broad cod can lay thousands of eggs during the spawning period, polar cod - about 10 million, and in the wild cod developed in the ovaries surprisingly up to 60 million eggs. Eggs, juveniles and small fish drift hundreds or even thousands of kilometers with the waves from the spawning site, but the newborn small fish do not feel comfortable and at ease in the water layer and always try to find a place to hide. Jellyfish provide them with this. Young haddock, cod and hake have been known to hide under the dome of a jellyfish and swim all over the ocean under its protection.

Cod remain interested in long return trips as they mature. Many cod gather in schools twice a year and embark on long journeys. The return journey of cod is closely related to the journey to the wintering grounds, the fattening grounds or the spawning grounds. The direction of their return journey depends on ocean currents and water temperatures.

Many subfamilies of the cod family are among the world's most important fished species. These include northern cod, haddock, blue whiting, toothcod, haddock, green cod, and hake (pollock). The most prominent and valuable cod is the Atlantic cod. This fish develops a passion for traveling when it reaches the age of three. From this point on (their life span is generally 20 to 25 years), they make an annual fall return trip, swimming 7 to 8 kilometers a day and night, and can swim a distance of 1,500 kilometers in 5 to 6 months. Once they reach the Norwegian coast, they stop to spawn in the Lofoten Islands area. The spawning period lasts several weeks, as they lay eggs every few days, usually two to four times. During this time fishermen compete to catch Atlantic cod, and most of the cod that come here to spawn become the fishermen's trophies. Cod, blue whiting and hake, in addition to the meat taste delicious, their liver is also very valuable, is the raw material for the manufacture of cod liver oil, rich in vitamins A and D.