Cod (local names: Datouqing, Datouyu, Datouyu, Mingtai fish, Shuikou fish, Guangkou fish, Datouxing fish, and stone oak fish). Pure cod refers to cod, which is divided into Atlantic cod (Gadus morhua), Greenland cod (Gadus ogac) and Pacific cod. [1] There are Pinnaceae in the coding order, and the common concept of cod is extended to Pinnaceae, with more than 50 species, most of which are distributed on the North Atlantic continental shelf. Important species are haddock, blue cod, green cod, marlin, Norwegian long-arm cod and cod. Cod is one of the largest fish caught in the world every year, which has important edible and economic value.

gingkgo

cod

Latin scientific name

Gadus

Another name

Slate cod

boundary

animal kingdom

door

chordata

Ancient yamen in China

A subclass of vertebrates.

summary

bony fish

subclass

Actinidia of Actinidinae

eye

Codiformes

suborder

Cod suborder

The branch of academic or vocational research.

Cod family

belong to

cod

spell

Snowy

English name

cod

catalogue

1 shape characteristics

Two kinds

3 distribution range

4 living habits

5 main value

Six nutrients

7 food guide

Cooking instruction

Cod straw mushroom porridge

8 true and false species

9 protection level

Appearance characteristics

cod

Cod is slender, slightly flat, with a big head and a big mouth. The upper jaw is slightly longer than the lower jaw, and the tail gradually tapers backward, generally 25-40 cm long and weighing 300-750 grams. The tentacles of the neck are equal to or slightly longer than the eye diameter. Both jaw and vomer have fluffy teeth. The small round scales covered on the body surface are easy to fall off, with obvious lateral lines, 3 dorsal fins and 2 gluteal fins, all of which are completely composed of fins without hard spines. Body color is diverse, from light green or light gray to brown or light black, and can also be dark red to bright red; The head, back and sides are grayish brown with irregular dark brown stripes, and the ventral surface is grayish white.

kind

There are three kinds of cod: Atlantic cod (Gadus morhua), Greenland cod (Gadus ogac) and Pacific cod (Gadus macrocephalus), which can be considered as pure cod in the traditional sense. [ 1]

Atlantic cod

Living in the northern part of the Atlantic Ocean, it is a cold-water fish, which can grow to nearly two meters long and weigh up to one or two hundred kilograms. Cod meat is tender, light, big and high in yield-it is said that people can walk on the sea during the flood season. Fishermen in northern Europe have been fishing Atlantic cod on a large scale since Viking times. There is a peninsula called Cape Cod in Massachusetts, USA, which was named by Cod merchants in the early years. In the famous Boston Tea Party, there were also "cod upstarts". /kloc-In the middle of the 0/9th century, fish and chips became the favorite fast food for working-class people in Britain. In the 20th century, the fishing technology became more and more advanced, and the number of cod decreased sharply. Fishermen from neighboring countries, including Britain, have come to Iceland by cod boat. At that time, Iceland's economy was heavily dependent on cod fishing. In order to protect the interests of local fishermen, since the 1950s, the Icelandic government has continuously revised its laws and expanded its jurisdiction. Britain and Iceland fought for cod for more than 20 years. Finally, under the mediation of NATO, Britain accepted the concept of 200 nautical miles exclusive economic zone advocated by Iceland.

Atlantic cod

In 2000, a study published by WWF showed that the global catch of Atlantic cod had decreased by 70% since 1970. Cod became an endangered species. Later, the Atlantic cod population, once considered pessimistic, gradually recovered, with an annual catch of about 800,000 tons. There is no Atlantic cod in China waters, but some cod fishing countries, such as Russian, transport their catch to the port of China. With the low cost of human resources in China, China's reprocessed cod products can be sold all over the world, and China has become the largest supplier of Atlantic cod products in the European market.

Cod, commonly known as cod, is a kind of marine fish that westerners like to eat. This was earlier than17th century, when immigrants from North America dried cod and sold it to Spain, Portugal and Britain. Since the 20th century, with the invention of refrigerator, cod is mostly exported as frozen fillets. The fish of cod is white, tender, firm and light. Cod liver oil also contains a lot of vitamins A and D, so it is often used to extract cod liver oil. Cod has triggered three wars between Britain and Iceland. Surprisingly, the huge Royal British Navy fleet was defeated by Icelandic gunboats transformed from small fishing boats, and the world's veteran naval powers lost these three wars in succession.

Pacific cod

Generally smaller than Atlantic cod, but it looks no different from Atlantic cod in appearance and tastes indistinguishable. Because Pacific countries don't have the cod complex like Europe, they have been relatively unknown. The Yellow Sea and Bohai Sea in China are also the producing areas of Pacific cod, but coastal residents pay little attention to them.

Greenland cod

It grows in the sea around the coastline of Greenland. Due to the low output, it rarely appears in the market.

distribution range

Distributed in both sides of the North Pacific Ocean and the North Atlantic Ocean, it generally inhabits near the bottom and is taken to the deep sea area from the nearshore. Native to the cold waters of the North Atlantic from northern Europe to Canada and the eastern United States. The main producers of cod in the world are Canada, Iceland, Norway and Russia, and Japan is mainly in Hokkaido.

China is mainly distributed in the Bohai Sea, the Yellow Sea and the northern part of the East China Sea. There are main fishing grounds in the north of the Yellow Sea, east-southeast of Shandong Higher Education, south of the island and south of the East China Sea.

Living habits

Cold water benthic fish feed on invertebrates and small fish. Habitat in the cold water area of the Yellow Sea in summer and autumn, and swim back to the coastal mud bottom area with a water depth of 50 ~ 80m in winter. Most cod live in the cold waters of the Pacific Ocean and the North Atlantic Ocean, and the water temperature is 0℃ ~ 16℃.

cod

Cod feeds on other fish and invertebrates, with large food intake and fast growth, and can grow to 1 m in about 10 years; It is a gluttonous migratory fish and eats a lot. Because of social life, it is easy to catch, and it has been a quite famous edible fish since ancient times. A female fish with strong reproductive ability and a body length of about 1 m can lay as many as 3 to 4 million eggs at a time. The reproductive cycle of the Yellow Sea is 1 ~ 2 months, with 340,000 ~ 830,000 eggs, and the eggs sink into the water with a diameter of 0.98 ~ 1.05 mm. ..

Arctic cod is a typical cold-water fish, which is distributed throughout the Arctic. When the temperature exceeds 5℃, they will disappear. It is a small and medium-sized fish, the longest of which can reach 36 cm, and it is one of the important economic fish in the Arctic.

In summer, Arctic cod mainly live on the edge of the frozen area of the Barents Sea in the Kara Sea. Juvenile Arctic cod feed on small phytoplankton and zooplankton. With the growth, the plankton it ate gradually changed from small to large, and some of them preyed on small fish.

By September every year, the Arctic cod began to migrate to the west and south, and laid eggs at sub-zero temperature in winter, which were floating eggs, and the number of eggs laid was 9000 ~ 18000. Because of the low water temperature, the incubation period is as long as 4 ~ 5 months.

Cod (4 pieces)

The growth rate of Arctic cod is rapid in the cold Arctic. The average body length is 17cm at the 3rd instar, 19.5cm at the 4th instar, 2 1cm at the 5th instar and 22cm at the 6th instar. Arctic cod can be up to 7 years old. The age of sexual maturity of Arctic cod is generally 4 years old, and most of them only lay eggs once in their lives, and stop eating during the spawning period. After spawning, some Arctic cod swim into estuaries or downstream rivers, and then enter the high seas. [2]

Main value

Generally inhabiting near the bottom (water depth 0-2740 meters), it belongs to cold-water bottom fish and is one of the marine economic fish produced in the northern coast. Its meat is white, fine and tender, and the entrance is not greasy. Many countries in the world regard cod as the main edible fish. In northern Europe, cod is known as the "nutritionist at the table". In addition to fresh food, it is also processed into various aquatic foods. In addition, cod liver oil is large in volume and rich in vitamins A and D, which is the raw material for extracting cod liver oil.

The oil extracted from cod liver oil is an important source of vitamin D. The milky white fish of cod is rich in lean meat and delicious, and the compactness of meat depends on the freshness and size of cod. Cod has a good protective effect on cardiovascular and cerebrovascular systems, among which steamed cod is light and refreshing, simple and easy to make, and has the effect of promoting blood circulation and relieving pain. [3]

Cod liver oil (oil content is 20 ~ 40%) can be extracted from cod liver oil, which is rich in vitamin A and vitamin D. Cod liver oil has inhibitory effect on mycobacterium tuberculosis, and the concentration of unsaturated acid can prevent bacteria from multiplying. Cod liver oil can also kill bacteria in infected wounds. Ointment made of cod liver oil can quickly liquefy gangrenous tissue. Cod pancreas contains a lot of insulin. 12000IU insulin can be extracted from 1kg pancreas, which has a good hypoglycemic effect and can be used to treat diabetes. Fish is rich in magnesium, which has a good protective effect on cardiovascular system and is conducive to preventing cardiovascular diseases such as hypertension and myocardial infarction. Small molecular peptides extracted from cod by modern bioengineering technology and enzyme engineering technology are rich in soluble calcium, with high biological safety and easy absorption by human body.

Cod (6 pieces)

1996 The global cod catch reached 107 1 10,000 tons, accounting for 12% of the total marine fishery output. The main fishing species belong to Pinnaceae, Haddock and Pinnaceae.

China's offshore fishing started from 1985 to 199 1, and large trawlers have been operating in the Bering high seas. Due to the overfishing of major fishing countries in the world, the pollock resources in the Bering high seas have been exhausted in a few years, and the emerging offshore fishing industry in China is in trouble. In the middle of the Sea of Okhotsk, there is a small high sea, which is long and narrow from north to south like a Pollock Strait, surrounded by Russia's 200-nautical-mile economic zone. At that time, Haifa, a refrigerated transport ship of ocean shipping company, accidentally discovered the "New World" when loading fish meal in Hubei. Several large Polish trawlers caught cod here, and then China's ocean-going fleet swarmed in, opening a new chapter in China's ocean-going fishing.

nutritional ingredient

Cod output (17 sheets)

Cod meat is delicious and nutritious. Protein in meat is higher than that of salmon, pomfret, pomfret and hairtail, while the fat content in meat is only 0.5% of that of shark, which is 0/7 times lower than that of salmon and 7 times lower than that of hairtail. Liver is rich in oil, not only DHA and DPA of common fish oil, but also vitamins A, D, E and other essential vitamins. The proportion of these nutrients in cod liver oil is the best proportion of the amount needed by human body every day. Therefore, the Nordic people call it a "nutritionist" at the dinner table.

Edible guide

Cooking instruction

Cod can be cooked in many ways, especially when dipped in sauce. Cod can be made into canned fish, dried cod or pickled smoked fish, and cod roe can be eaten fresh, smoked or pickled. Cod's tongue and liver are also edible. black

cod

Line cod is usually smoked or pickled, and small cod is usually made into dried fish.

In order to remove the salt from pickled cod, the fish was put into a container, which was put into a sink, and a small stream of water was injected into the sink. When the sink is filled with water, the salt will be washed away. Pickled dried fish need to be soaked in water for 8~ 12 hours before cooking. When cooking cod, it is not advisable to boil it. You can put it in clear soup and simmer for about 8 minutes, or you can put it in the cooked liquid for a while, then quickly take the pot out of the stove and set it aside 15 minutes. [3]

Cod straw mushroom porridge

Ingredients: 1 bowl of thick porridge, 200g cod, 50g straw mushroom and appropriate amount of mung bean; 240 grams of fresh soup, 2 tablespoons of refined salt, monosodium glutamate 1/2, 4 tablespoons of sesame oil 1/4, and appropriate amounts of onion and ginger.

working methods

1: clean cod and cut into rectangular slices; Blanch straw mushrooms and string beans with clear water, remove and drain for later use.

2: Boil the seasoning soup in a pot, add Jiang Mo and Volvariella volvacea, add thick porridge to boil, add cod fillets to cook, add refined salt, monosodium glutamate and sesame oil, mix well, add green beans, sprinkle with chopped green onion, and take out the pot and put into bowls. [4]

True and false species

The market including silver cod, water cod, dragon cod and oily fish are not pure cod. Silver cod, alias black cod and blue cod. But taxonomically, it belongs to gymnodinidae and Siluriformes. Oil fish is a general term for echinopus macrocephalus and Sparus heteropointus. Its appearance is somewhat similar to that of cod, but it is not a population. Because the fish sold in the market are all cut into pieces, it is difficult for ordinary consumers to distinguish them by appearance. Oil fish contains wax fat that the human body can't digest, which is difficult for the human body to digest. Some people will accumulate in the rectum after eating, leading to diarrhea, gastrointestinal spasm and other discomfort. The commercial value of oily fish is not high, and it belongs to low-priced fish. Because of its high oil content, it is mainly used for refining industrial lubricants. [5]

Since 2009, it has been reported in many cities in China that oily fish were sold as cod, causing diarrhea among consumers [6].

cod

Because the mechanism of diarrhea caused by oily fish is not completely clear, many countries in Europe and America put oily fish on the list of prohibited foods, and many countries prohibit or do not recommend national edible fish. The United States imposed an embargo on this kind of fish in the 1990s, and now it has been lifted, but the US Food and Drug Administration still opposes the import of oily fish and interstate trade. The Japanese Ministry of Health, Labor and Welfare lists oily fish as "poisonous fish" and prohibits its import. In August, 2007, the China and Hongkong Food Safety Centers issued the Guidelines for the Labeling and Labeling of Oilfish/Cod, suggesting that all importers should adopt the common names "wax oil fish" and "oily fish" of Japanese Spinosaurus and Japanese Allosaurus, and other common names such as "Cod" should not be used to distinguish between industries and consumers.

By the end of 20 13, there were no laws and regulations prohibiting or restricting edible oil fish in China, only a few fish such as puffer fish were restricted.

Dragon cod, Round Cod, Flat Cod, Silver Cod, Blue Cod, Golden Cod, Black Cod, Narrow Cod, Blue Cod, Rock Cod and Water Cod, which kinds of cod with different names have you eaten? Although the real cod is facing the danger of extinction, there are still many fish dishes called cod in the catering industry, but in the real biological classification, most of them are not cod, but only the name of a commodity. Even most chefs can't tell which of these fish is the real cod. If these fish are decapitated, dirty, boned, peeled, diced or sliced, their appearance will be more difficult to distinguish, almost identical to the real cod meat.

In the biological classification, cod belongs to the animal kingdom, chordates, Actinidia, coding orders, Pinctadaceae and cod. Only the fishes of Codiformes, Codidae and Codidae are real cod, and there are only three species, namely Pacific cod, Atlantic cod and Greenland cod. [6] Many cod in the market either come from the same family, different genera or different families of the same purpose, or do not belong to the coding order. These fish, which have almost nothing to do with cod, will be named cod because cod is on the verge of extinction. After the Atlantic cod fishing grounds are closed one by one, the market is looking for alternatives. I don't know when it has become a practice to label other non-cod with the name of cod.

Protection level

Cod is on the verge of extinction

Overfishing has led to a sharp decline in the number of Atlantic cod. From the 1960s to the early 1990s, the number of Atlantic cod in Newfoundland waters plummeted by 99.9%, which was one of the most serious "collapses" of existing marine and even terrestrial animals in history. Although countries have implemented a series of bans since 1993, expecting to see the recovery of the cod population, after more than years of fishing restrictions or even bans, the cod population has not shown signs of rebounding, but has remained at the lowest point in history, and the individual size is far less than before. For decades, the average size of adult cod has decreased by about 20%. Because the largest and fastest-growing cod has almost dried up, the growth and reproduction of existing cod are very slow.

More and more evidence shows that the so-called "long-term thinking" of human beings-only catching big fish and not releasing small fish, actually affects the evolution of species unconsciously, and finally leads to the terrible consequence of "survival of the weak". After analyzing the data of nearly 30 years, Norwegian scientists have confirmed that catching large individuals in large quantities will lead to the reduction of the average size of cod. Compared with their "ancestors", cod are small, mature early, lay eggs early and weak. This evolutionary trend actually appeared before the collapse of cod population. Scientists point out that fishermen should put the strongest cod back into the sea. Only in this way can we ensure their normal reproduction. The best way to protect fishery resources is not to catch big fish but to catch them casually. In this way, those strong individuals who shoulder the reproductive mission will not have too much evolutionary pressure.

Canadian scientists use a perfect fishery reserve model to predict the future of cod population in Newfoundland. These models consider the reproduction rate of cod population-based on the proportion of cod larvae in the population, the growth status of adult individuals and the natural mortality rate. The final prediction is regrettable: if limited fishing is allowed, the cod population living in the southern bay will be extinct in the next 20 years. Even if cod fishing is completely banned, these populations will disappear within 38 years. In addition, although most other cod populations living outside Canada remain intact, they may encounter the same problems in the next few years.

French scientists also found that the rising ocean temperature caused by global warming is bringing double disasters to cod. Since the mid-1980s, the rising of seawater temperature has changed the plankton ecosystem and brought long-term changes to the growth environment of cod. Juvenile cod mainly feed on marine plankton. The increase of seawater temperature has greatly changed the number and seasonal variation of plankton, thus "disturbing" the normal food supply of cod. Therefore, the number of cod that can develop and survive normally is decreasing day by day.