Cod is not only one of the most popular and affordable fish, but also a true wonder of nature and history. This fish has been an integral part of the human diet since ancient times. From the Viking raids to the medieval trade routes, cod was an important commodity that connected the lives of different peoples and cultures.

Historical sources indicate that cod was fished and salted as early as the 9th century. In the Middle Ages, it became a major trade item between Northern Europe and the Mediterranean. Interestingly, the cod trade was one of the reasons for the growth of historic ports such as Bergen in Norway and Bristol in England.

But cod is not only a historical symbol - it also amazes with its biodiversity and health benefits. This elegant sea dweller, characterized by white, low-calorie meat and minimal bone content, is today a favorite of both culinary experts and supporters of a healthy lifestyle. In addition, cod liver oil has been considered a natural medicine for centuries, especially in northern regions where sunlight was lacking.

In this article, we will look at the cod species, habitats, nutritional value, and interesting facts that have made this fish a true treasure of the seas.

What does cod look like?

Cod is a fish whose appearance and biological properties have deservedly fascinated both scientists and fishermen. Its body is elongated and graceful. The cod's head is large and proportional to the height of the body. Round eyes with brownish iris tones are located on the upper part of the head. The cod's gill covers, located at the end of the head, elegantly merge into the pectoral fins.

The cod has three dorsal fins arranged in a row along its dorsal line, all of whose rays are elastic and free of sharp spines. The end of the body is completed by a fin with undivided lobes, and in the lower part there are two anal fins. These features make the cod perfectly adapted to live in various water layers.

Although cod often feeds on the bottom, its color is adapted to pelagic (open sea) living conditions. The dorsal part of the body is dark, the sides are lighter, and the belly is milky white, sometimes yellowish. The color range depends on the place of residence: from yellowish-gray to brownish. The body is complemented by small gray or gray-brown spots, which are scattered on the back and sides.

The lateral line – a thin, light band – is clearly visible and slightly curved at the first dorsal fin. In the head area, the lateral line transitions into a complex network of sensors called sensory canals, which help the cod orient itself and detect its surroundings.

Atlantic cod – the largest member of this family. It can grow up to 1.7 m in length and weigh as much as 90 kg. However, in reality, fishermen usually catch smaller cod, up to 1 m in length. Other species, such as the Pacific cod, are slightly smaller. Pollock, often considered the smallest member of the cod family, grows up to 1 m in length and weighs about 3.8 kg.

Cod species and subspecies

The cod family includes several main species, which are sometimes divided into subspecies. Each species has distinctive external features, different sizes, and names derived from their habitats. The cod classification also includes pollock.

Main types of cod

• Atlantic cod
• Pacific (Far Eastern) cod
• Greenland cod
• Arctic cod
• Pollock

Atlantic cod

Atlantic cod is the largest member of the cod family. It is divided into three main subspecies:

• Atlantic cod
• White Sea cod
• Baltic cod

Atlantic cod The cod lives in temperate zones and in the northeastern Atlantic Ocean, the Barents Sea, and in waters from the coast of North Carolina to Greenland. This cod can grow up to 2 meters long. Its belly is white or yellowish, and its back is greenish or brown with gray-brown spots.

White Sea cod It is found in the waters of the White Sea and its bays - Kandalaksha, Dvinsk and Onega. It is smaller than the Atlantic cod, its length does not exceed 60 cm, and its color is darker.

Baltic cod It is mostly found in the middle of the Baltic Sea, with smaller populations in the Gulfs of Bothnia and Finland. It can grow up to 1 meter in length and weigh up to 12 kg.

Pacific cod

Pacific cod, also known as Far Eastern cod, is abundant in the northern Pacific Ocean. It is often found in the Sea of Okhotsk, the Sea of Japan, and the Bering Sea. This species is distinguished by its large head, and its average length ranges from 50 to 90 cm.

Greenland cod

Greenland cod is smaller than Atlantic cod. Its maximum length reaches 80 cm. This species lives in the coastal waters of the island of Greenland.

Arctic cod

Arctic cod has two main subspecies:

• East Siberian cod, found in coastal waters of North America, Greenland, and Siberia. It reaches a length of up to 50 cm and a weight of up to 1.5 kg.
• Ice cod, which lives in the western Arctic Ocean, as well as along the northern and northwestern coasts of Greenland. It grows to a length of up to 30 cm and has a relatively large head, and the antenna is often poorly developed or absent.

Pollock

Pollock is different from other cod species. Its body is narrower, it is smaller. The back is dark, gray or almost black, and the body is covered with small silvery scales. Pollock is found in abundance in the waters of the Pacific Ocean, most often in the Seas of Okhotsk, Japan and Bering.

Cod lifestyle

Cod inhabits the midwater and bottom zones of the North Atlantic Ocean. It is found in both American and European coastal waters. In North America, Atlantic cod is distributed from Cape Cod to Greenland, while in European waters it migrates from the Atlantic coast of France to the southeastern Barents Sea.

Cod often feed in bottom areas, but their body shape, size, and the position of the corner of their mouth indicate that midwater layers are also an important habitat for this fish.

Not only the location in the water column, but also the temperature and salinity of the water are of great importance for the life of cod. Different species of cod have adapted to different salinity conditions:

• Pacific cod likes extremely salty water (33.5 ‰–34.5 ‰).
• Baltic and White Sea cod feels good in water with a salinity of 20 ‰–25 ‰.

All cod species prefer cool waters – their optimal temperature is up to 10°C.

Cod are constantly migrating fish. There are three main reasons why schools of cod change location:

• Feeding – cod follow their prey, such as schools of herring.
• Temperature changes – cod migrate to better climatic conditions.
• Spawning – the most important reason for migration, when fish travel to specific locations to spawn.

Cod is a predatory fish and is not demanding in terms of prey. Young fish feed on planktonic crustaceans and small fish. As the cod grows, its diet becomes more diverse - in addition to small bottom animals, larger fish are also added.

Adult cod can even feed on their own family members, such as word or NavajoThese relatives become prey no less often than young cod of the same species. Large cod often hunt herring.

Cod is a flexible and adaptable fish that contributes to the ecological balance of the oceans and is an indispensable link between predators and prey. Its ability to adapt to various conditions, as well as its constant migration and feeding habits, make it one of the most interesting marine inhabitants.

How cod spawn

Cod spawning begins at the beginning of winter, in January, and ends at the end of spring. The most intensive spawning period is from February to April. The main spawning grounds for Atlantic cod are in Norwegian waters, where large schools of mature fish gather.

Powerful schools of Atlantic cod form in the spawning grounds, in the pelagic zone. They consist of females aged 3–8 years and males aged 4–9 years. All spawning fish are at least 50–55 cm long, and their average age is about 6 years. The average length of the fish reaches 70 cm.

Females release a large number of eggs directly into the water layer. The fecundity of a large and healthy cod can exceed 900 thousand eggs. Each egg is transparent, about 1.5 mm in diameter. After spawning, the female completes her mission, and the male releases his sperm into the water layer, hoping that they will fertilize the eggs.

Within 3-4 weeks, the fertilized eggs develop into larvae, which are no longer than 4 mm in length. For the first few days, the larvae feed on the corpus luteum, and then begin to feed on plankton. Currents usually carry the eggs to coastal areas, where the young can find shelter and more food.

Cod liver oil

Cod liver oil has been widely used since the 19th century, when Northern Europeans used it as a natural remedy for rickets. Its value grew significantly in the 20th century, when scientists demonstrated the oil's benefits for bone and heart health.

Cod liver oil is a unique natural product that has long been valued for its beneficial properties and nutritional value. This oil, extracted from cod liver, is one of the most important natural sources of omega-3 fatty acids, vitamins A and D. It not only strengthens the immune system, but also helps maintain a healthy heart, bones and skin.

Cod liver oil is most commonly taken in liquid or capsule form. The recommended dosage for adults is 1 to 2 teaspoons per day, but it is important to consult a doctor before taking it.

Cod in cooking

The white, firm and lean flesh of cod is a true gourmet's gift. This fish is not only healthy, but also very tasty.

Interestingly, the size and age of the cod have a significant impact on the quality of its meat. Huge cod, even up to 1.8 meters long, are usually too tough, so they are used for canning. The best cod are 40-80 cm long, which are no younger than three years old. This age is like a “golden period”, because older cod, due to long migrations and the accumulation of muscle mass, lose some of their delicate flavor.

Cod meat is special because of its texture. It is “firm” and elastic, making it ideal for making cutlets – they do not lose their shape when fried. This is due to the leanness of cod, as most of the fat is stored in the liver, which is enriched with omega-3 fatty acids. Thanks to these properties, cod fillets not only look great, but also do not lose their shape when cooked in various ways.

The Portuguese were the first to appreciate the taste and durability of cod. As true fishermen, they noticed that this fish is not only delicious, but also perfectly suitable for long-term storage. Especially dried - a cod fillet and 500 grams of salt create a real miracle in 3-4 days. During drying, the meat releases a lot of moisture, becomes dry and almost grainy.