Pacific bluefin tuna. bluefin tuna

Bluefin tuna is nicknamed "bluefin", it is also called sea beef. Tuna is a high-protein fish containing selenium, omega-3 acid, sodium and potassium. About bluefin tuna Marina Smooth told the chief chef of the Sumosan restaurant chain in London, Moscow and Kiev Bubker Belkhit.

Does bluefin tuna put on weight quickly?

- Tuna is a real hero, he quickly gains weight, because he eats very well, more precisely, he cannot go without food for a long time. He prowls in search of favorite delicacies - squid, eels or small fish. If the tuna does not eat, then it snacks, the insatiable fish constantly chews something, even algae, and does not refuse plankton. A good appetite gives results, in a fairly short period of time, tuna gains 250 kg - and this is an average figure, although even with this weight, tuna is a real torpedo the size of a person. Fishermen say that the largest tuna they have ever come across weighed about 700 kg. It could only be placed on three shifted tables, it occupied an entire room. I have tried gigantic-sized fish, but, to my great disappointment, the big tuna turned out to be tasteless. It is better to choose a copy up to 350 kg.

Is bluefin tuna a solitary fish?

— No, he obediently holds on to the joint, although he could afford freedom. However, large dolphins and killer whales also love the company. A school of tuna rushes through the waves, sweeping away everything edible in its path. If people had an appetite like tuna, supermarket shelves would always be empty, we would constantly eat on the go.

- A big weight Does it prevent bluefin tuna from swimming?

“Speed, continuous movement, and stamina are the qualities of a fat giant. Bluefin tuna is able to rush under water at a speed of 70 km / h. It is beautiful in every way, the body of the tuna is streamlined, a real submarine. Tuna looks like a spindle, by the way, not only externally. For example, killer whales take care of themselves - they swim no more than five kilometers per hour and even hunt lazily: they press a school of fish to the shore and muffle it with tail blows, in turn, so as not to get tired during the hunt. Tuna, on the contrary, is a racer, he is always in a hurry somewhere, rushing somewhere - a slippery, streamlined torpedo, and also very beautiful.

Why does bluefin tuna look like beef?

- Warmblooded bluefin tuna is a rarity among fish. The circulatory system warms up the muscles, carries oxygen throughout the body, which allows it to move. Tuna differs significantly from other fish, for example, it does not pump water through the gills, so it always swims with its mouth open and is in constant motion. If the tuna stops, it will simply suffocate. Hence the appetite unique abilities restless swimmer. The tuna is amazingly built, with flat eyes and the ability to fold its fins, making it incredibly agile and streamlined. He glides in the water, lives in movement and enjoys it.

Is bluefin tuna different from the rest?

- Outwardly, fishermen determine it by the shape of its back - the bluefin has slightly different fins, and it is invariably larger than its counterparts. The bluefin tuna has a pearly white belly and a metallic blue body that is hard to spot, and tuna love to play hide-and-seek. They find a pod of dolphins and walk with them. The latter, unfortunately, because of the tuna often fall into the net. Americans, by the way, are trying to protect dolphins. If tuna fishing is done incorrectly, they can embargo and deny imports, as was the case with Mexico.

— And where do they catch the most delicious tuna?

- Bluefin tuna is the most delicious of all representatives of the breed. He loves to chase prey, but they are also willingly chasing him, catching him in tropical latitudes. It's hard to believe, but the largest, fattest species live in the cool northern waters. It is even more difficult to imagine tuna in the Azov or Black Sea, however, it happens here too. The geography of the movements of bluefin tuna is surprising - here are the cold waters of Iceland and the tropical waters of the Gulf of Mexico. Tuna comes to the Mediterranean Sea or to the coast of Mexico to lay eggs. Experienced fishermen say that tuna is able to return to warm waters. Distance is not a problem for him.

Does bluefin tuna taste different from others?

- Real bluefin tuna is a rarity, only a professional will distinguish its meat by appearance. Bluefin tuna has no fishy taste at all and a hint of the smell of the sea. The Japanese, selling tuna, make an incision on it, like on a watermelon: the buyer approaches, tries, looks at the color. The Japanese value tuna very much, for them it is like gold.

Is bluefin tuna bright red?

- To prepare sashimi, they take thick pieces of the most delicious part - the abdomen, it is also called toro. At the same time, an inexperienced cook may panic - the meat is pink, the same as that of other types of tuna. But literally after a few minutes of interaction with air, it becomes thick red, as it should be.

Yesterday, the first fish auction of the year was held at the Tsukiji fish market in Tokyo, where another record was broken - the buyer paid $ 736,000 for a carcass of bluefin tuna weighing 269 kg. The owner of a Tokyo chain of sushi restaurants became the owner of such a valuable tuna. He expressed the hope that his purchase will at least to some extent help to resume the buying boom in Japan, which went through the worst last year. natural disasters.

(Total 11 photos)

1. Bluefin tuna caught off the coast of Aomori Prefecture sold at an auction in Tokyo for a record 56.49 million yen (about $736,000). The first auction this year took place yesterday, January 5, at the world's largest fish market in Tokyo, Tsukiji.

2. The 269 kg fish presented at the auction was already gutted, that is, its weight at the time of capture was more.

3. The winner of the auction and the owner of the 269 kg giant tuna was Kiyoshi Kimura, president of Kiyomura, which represents a chain of sushi restaurants.

4. The amount for which bluefin tuna was purchased exceeded last year, when a fish weighing 342 kg was purchased for 32.49 million yen (about 400 thousand US dollars).

5. Another record, according to market representative Yutaka Hasegawa, was the price per kilogram of fish - almost 3 thousand dollars.

6. Decades of uncontrolled fishing led to a global crisis in the tuna market. As a result, some Western countries are calling for a complete ban on the Atlantic tuna trade.

7. Japan consumes three-quarters of the world's bluefin tuna, which is highly valued as an ingredient in sushi. Bluefin tuna is prized for its red meat, which can be eaten raw.

8. With each passing year, Japan, which remains one of the world's largest consumer markets for tuna, finds it increasingly difficult to secure a reliable supply of this delicacy.

9. The international catch quota for bluefin tuna is gradually being reduced, while demand for this fish is growing in other Asian countries.

10. In Japan, it is known as “kuro maguro” (black tuna), and sushi connoisseurs dubbed it “black diamond” for its rarity.

The magnificent fish was divided into 10,000 pieces and sold at the most common price, as a sign that people affected by the tsunami needed positive. The Japanese appreciated Mr. Kimura's generosity very highly.

11. A piece of "otoro" - a fat belly - in the best Tokyo restaurants can cost 2,000 yen ($22).

Tuna is a fish with a torpedo-shaped body that is ideal for constant movement. Moreover, these fish are constantly moving, not stopping for a minute. The energy that the tuna expends when swimming made its blood several degrees higher than the temperature of the surrounding water.

Tuna move in large flocks and cover long distances in search of food, moving at speeds up to 77 km / h.

Albacore

Albacore is a type of tuna that is sometimes referred to as albacore tuna. This species is distributed in almost all waters of the oceans, with the exception of the polar regions. Albacore is a fairly medium-sized representative of the family, reaching a length of almost 1.5 m. It is a very significant object of industrial fishing due to high-quality meat. The meat of the albacore tuna is most widely distributed in the United States, where the species is often referred to simply as "tuna". Albacore is a favorite trophy of sea fishermen.

bigeye tuna

Bigeye tuna is a larger member of the family, which grows up to 2.5 m. The maximum recorded weight of this fish was 400 kg. Distinctive feature This tuna is a wide fin that has 13 or 14 dorsal spines. During migration, bigeye tuna can descend into cold deep layers of water, visiting which is not typical for most species of the family. In these places, the tuna actively feeds, while its heart functions more actively, giving vitality fish. But in the cold depths, the fish cannot stay for a long time and must necessarily warm themselves in the warmth on the surface.

blackfin tuna

Blackfin tuna is the smallest. Does not exceed 1 m in length and 20 kg in weight. It lives only in the west of the Atlantic Ocean off the coast of Brazil. Unlike their counterparts, blackfins prefer to eat small larvae, shrimps, crabs and squids. Of course, they also prey on small fish, but to a lesser extent. This species ages very quickly, and a 5-year-old fish is already considered old.

bluefin tuna

The bluefin tuna is a resident of the Pacific Ocean. One of the largest and fastest fish. With warm blood that warms the fish's muscles for extra energy, the bluefin tuna is a fast predator. Its diet is rich in herring, mackerel and squid, which slower predators fail to catch.

Atlantic bluefin tuna

Atlantic bluefin tuna - found throughout the Atlantic. In the past, this type of tuna was found in the Black Sea, but at present the Black Sea population has disappeared. Visually, the body of the bluefin tuna is similar to the Pacific bluefin, and in the past they were often confused, mistaking for one species. This tuna is the most valuable among other species. There are cases of buying bluefin tuna carcasses for more than 100 thousand dollars. The Japanese are willing to pay that kind of money for tuna meat, which is used in the preparation of many national dishes.

"King of all fish" - this title in 1922, the tuna received from Ernest Hemingway, who was impressed by the sparkling live torpedo that cut through the sea waves off the coast of Spain.

Description of tuna

Ichthyologists recognize tuna as perhaps the most perfect inhabitant of the ocean. These sea ​​fish, whose name goes back to other Greek. root "thynō" (to throw), are in the family Scombridae and form 5 genera with 15 species. Most species do not have a swim bladder. Tunas are very different in size (length and weight) - so mackerel tuna grows up to only half a meter with a weight of 1.8 kg, while bluefin tuna gains up to 300-500 kg with a length of 2 to 4.6 m.

The genus of small tuna includes:

• skipjack, aka striped tuna;
• southern tuna;
• spotted little tuna;
• mackerel tuna;
• Atlantic small tuna.

The genus of true tuna is represented by the most impressive species, such as:

• longfin tuna;
• bigeye tuna;
• yellowfin tuna;
• ordinary (blue / cyan).

The latter pleases fishermen with excellent specimens: it is known, for example, that in 1979, bluefin tuna was caught near Canada, stretching almost 680 kg.

Appearance

Tuna is incredible powerful creation, which nature has rewarded with perfect anatomy and revolutionary biological adaptations. All tunas have an elongated, spindle-shaped torso, which helps them gain enviable speed and cover great distances. In addition, for the speed and duration of swimming, one must thank the optimal shape of the dorsal, sickle-like fin.

Other benefits of the genus Thunnus include:

• unusually strong tail fin;
• increased rate of gas exchange;
• amazing biochemistry/physiology of the heart and blood vessels;
• high hemoglobin level;
• wide gills that filter the water so that the tuna receives 50% of its oxygen (for other fish - 25-33%);
• an exemplary thermoregulation system that delivers heat to the eyes, brain, muscles and abdominal cavity.

Due to the latter circumstance, the tuna body is always warmer (by 9-14 ° C) environment, while the own temperature of most fish coincides with the temperature of the water. The explanation is simple - they lose heat from muscle work, since blood continuously flows through the gill capillaries: here it is not only enriched with oxygen, but also cools down to water temperature.

Important! Only an additional heat exchanger (countercurrent) placed between the gills and other tissues can raise the body temperature. All tunas have this natural heat exchanger.

Thanks to him, the bluefin tuna maintains its body temperature at +27+28 °C even at a kilometer depth, where the water does not warm up above +5 °C. Warm-bloodedness is responsible for intense muscle activity, which provides tuna with excellent speed. The built-in tuna heat exchanger is a network of subcutaneous vessels that supply blood to the lateral muscles, where the main role is assigned to the red muscles (muscle fibers of a special structure adjacent to the spinal column).

The vessels that irrigate the red lateral muscles with blood form an intricate ornament of intertwined veins and arteries, through which blood runs in opposite directions. The venous blood of tuna (heated by the work of the muscles and pushed out by the cardiac ventricle) transfers its heat not to the water, but to the arterial (counter) blood filtered by the gills. And the muscles of the fish are washed by the already warm blood flow.

The first to notice and describe this morphological feature of the genus Thunnus was the Japanese researcher K. Kisinuye. He also proposed to separate all the tuna into an independent detachment, but, unfortunately, he did not wait for the support of his colleagues.

Behavior and lifestyle

Tunas are considered social animals that are characterized by pack behavior - they gather in large communities and hunt in groups. In search of provisions, these pelagic fish are ready to make throws at maximum distances, especially since they can always count on their stayer talents.

Going to hunt, tuna line up in a curved line (similar to the string of a stretched bow) and begin to drive prey at top speed. By the way, permanent swimming is inherent in the very biology of the genus Thunnus. Stopping threatens them with death, since the respiratory process is triggered by the transverse bending of the body, coming from the caudal fin. Moving forward also provides a continuous flow of water through the open mouth to the gills.

Lifespan

The life span of these amazing inhabitants of the ocean depends on the species - the more massive its representatives, the longer life. The long-lived list includes bluefin tuna (35-50 years old), Australian tuna (20-40 years old) and Pacific bluefin tuna (15-26 years old). Yellowfin tuna (5–9) and mackerel tuna (5 years) linger least of all in this world.

Range, habitats

Tunas somewhat distanced themselves from other mackerels over 40 million years ago, settling throughout the oceans (with the exception of the polar seas).

It is interesting! Already in the Stone Age, detailed images of fish appeared in the caves of Sicily, and in the Bronze and Iron Ages Mediterranean fishermen (Greeks, Phoenicians, Romans, Turks and Moroccans) counted the days until tuna spawned.

Not so long ago, the range of common tuna was extremely wide and covered the entire Atlantic Ocean, from the Canary Islands to the North Sea, as well as Norway (where it swam in the summer). Bluefin tuna was a habitual inhabitant of the Mediterranean Sea, occasionally entering the Black Sea. It was also found off the Atlantic coast of America, as well as in the waters of East Africa, Australia, Chile, New Zealand and Peru. Currently, the range of bluefin tuna has noticeably narrowed. The habitats of small tuna are distributed as follows:

• southern tuna - subtropical waters of the southern hemisphere (New Zealand, South Africa, Tasmania and Uruguay);
• mackerel tuna - coastal areas of warm seas;
• spotted small tuna - Indian Ocean and the Western Pacific;
• Atlantic smallfin tuna - Africa, America and the Mediterranean;
• skipjack (striped tuna) - tropical and subtropical regions of the Pacific Ocean.

Diet, food

Tunas, especially the largest ones (blue ones), eat almost everything that is in the thickness of the sea - it floats or lies at the bottom.

Suitable food for tuna are:

• schooling fish, including herring, mackerel, hake and pollock;
• flounder;
• squid and octopus;
• sardine and anchovy;
• small shark species;
• crustaceans, including crabs;
• cephalopods;
• sessile lips.

Fishermen and ichthyologists easily recognize the places where tuna deal with herring - its sparkling scales twist into funnels, which gradually lose speed and slowly dissolve. And only individual scales, which did not have time to sink to the bottom, remind us that tuna recently dined here.

Tuna breeding

Previously, ichthyologists were sure that the depths of the North Atlantic are inhabited by two herds of common tunas - one lives in the Western Atlantic and spawns in Gulf of Mexico, and the second lives in the Eastern Atlantic, leaving for spawning in the Mediterranean Sea.

Important! It was from this hypothesis that the International Commission for the Protection of Atlantic Tuna proceeded, setting quotas for its catch. Fishing was limited in the Western Atlantic, but allowed (in larger volumes) in the Eastern.

Over time, the thesis about 2 Atlantic stocks was recognized as incorrect, which was greatly facilitated by the marking of fish (which started in the middle of the last century) and the use of molecular genetic methods. For more than 60 years, it has been found out that tuna do spawn in two sectors (the Gulf of Mexico and the Mediterranean Sea), but individual fish easily migrate from one place to another, which means that the population is one.

Each zone has its own breeding season. In the Gulf of Mexico, tuna start spawning from mid-April to June, when the water warms up to +22.6 +27.5 °C. For most tuna, the first spawning does not occur before 12 years, although puberty occurs at 8–10 years, when the fish grows to 2 m. In the Mediterranean, fertility occurs much earlier - after reaching 3 years of age. Spawning itself occurs in summer, in June - July.

Tunas are highly fertile. Large individuals produce about 10 million eggs (1.0–1.1 cm in size). After some time, a larva 1–1.5 cm tall hatches from each egg with a fat drop. All larvae stray into flocks on the surface of the water.

And now let's see how they are traded ...

In Japan, traditional auctions were held, where the largest bluefin tuna caught was sold. This year, the largest representative of this species weighed 180 kilograms, and the owner of the Kiyomura sushi restaurant chain once again became its buyer.

According to Kiyoshi Kimura, this year the main fish of the year cost his restaurant chain incredibly cheap. Only $200 per kilogram of live weight. The total cost of bluefin tuna was $37,500. And this is true, considering that two years ago, the head of the chain laid out a record $1.8 million for bluefin tuna, which was only 42 kilograms heavier than the current one. According to the signs, this is not very good sign in relation to the species itself and the fishing industry in Japan as a whole.

Photo 2.

Environmentalists argued back in 2010 that bluefin tuna is endangered and urgent action needs to be taken to save it. Proposal to ban the export of Atlantic bluefin tuna, known for its juicy red-pink meat, cut supplies and drive up prices in Japan, the world's largest consumer and importer of fish.

Japan buys almost 80 percent of the annual catch of this fish.

Some Japanese fear the new ban will affect their lifestyle as the fish is used to make sushi, a traditional Japanese food.

Any ban would have a big cultural and economic impact, says Massageu Nakazawa, a 63-year-old fish market vendor.

Signatory countries to the Convention on International Trade in Species of Wild Flora and Fauna will consider the proposed ban at a meeting in Qatar in March.

If the ban is approved, bluefin tuna will be mentioned in the first annex to the Convention, which will allow only domestic consumption of fish in the EU countries. Activists say that this will significantly reduce the catch, since shipments to Japan will be prohibited.

The Japanese fear that this ban could open the door to new bans, such as the trade in other types of tuna.

Bluefin tuna, found in the Atlantic and Pacific Oceans, is the most common species. However, according to environmentalists, the population of these fish has declined by 75 percent since 1957 and continues to decline.

The International Commission for the Conservation of Bluefin Tuna has already set catch quotas and reduced them in 2010 from 24,250 tons to 14,900. But scientists say that only a ban on trade will allow the population to recover.

Photo 3.

With each passing year, Japan, which remains one of the world's largest consumer markets for tuna, finds it increasingly difficult to secure a reliable supply. The international catch quota is gradually decreasing, while the demand for this fish is growing in other countries of the Asian region, especially in China.

Photo 4.

Over the past 25 years, bluefin tuna fished in the Sea of ​​Japan off the coast of Tottori Prefecture have become several times lighter in weight. Such data was published on Tuesday by the Kyodo news agency, citing the fishing inspection of the port of Sakaiminato.

A quarter of a century ago, bluefin tuna, one of the most popular fish among local gourmets, weighed between 110 and 160 kg on average. In the 1990s, this figure dropped to 70 kg, and now it has fallen to 44 kg. At the same time, the volume of tuna fishing in the port of Sakaiminato is constantly growing. In the 1990s, it reached 10 thousand per year, and now fishermen annually deliver from 20 to 40 thousand tuna to the port. This accounts for 10 to 20% of the bluefin catch in all of Japan.

According to Associate Professor Toshio Katsukawa of Mie University, the bluefin tuna fished off the coast of Japan has "lost" so noticeably, as more and more young individuals get into the nets of fishermen, who do not have time to "work up the weight." “Big tunas are rapidly disappearing,” said the scientist, who is considered an authority on the conservation of the natural resources of the sea, “because of overfishing. Restrictions must be introduced, otherwise it will adversely affect the reproduction of their livestock, ”said Katsukawa, concerned about the current situation.

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