Useful properties of tuna. Beneficial properties of tuna for humans Tuna is a fatty fish
“King of all fish” - this title was given to tuna in 1922 by Ernest Hemingway, who was impressed by the sparkling living torpedo that cut through 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 ancient Greek. root "thynō" (throw), are in the family Scombridae and form 5 genera with 15 species. Most species do not have a swim bladder. Tunas differ greatly in size (length and weight) - for example, mackerel tuna grows 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, also known as skipjack tuna;
- southern tuna;
- spotted small 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-sized specimens: it is known, for example, that in 1979 a bluefin tuna weighing almost 680 kg was caught near Canada.
Appearance
Tuna - incredible powerful creature, which nature has awarded with ideal anatomy and revolutionary biological adaptations. All tuna have an elongated, spindle-like body, which helps them gain enviable speed and cover enormous distances. In addition, for the speed and duration of swimming, we must thank the optimal shape of the dorsal fin, resembling a sickle.
Other benefits of the Thunnus genus include:
- unusually strong caudal fin;
- increased rate of gas exchange;
- amazing biochemistry/physiology of the heart and blood vessels;
- high hemoglobin level;
- wide gills that filter water so that tuna receives 50% of its oxygen (in other fish - 25-33%);
- an exemplary thermoregulatory system that supplies heat to the eyes, brain, muscles and abdomen.
Due to the latter circumstance, the body of tuna is always warmer (by 9−14°C) environment, while the own temperature of most fish coincides with the water temperature. The explanation is simple - they lose heat from muscular work, as blood continuously flows through the gill capillaries: here it is not only enriched with oxygen, but also cools down to the temperature of the water.
Important! Only an additional heat exchanger (counterflow), placed between the gills and other tissues, can increase body temperature. All tuna have this natural heat exchanger.
Thanks to it, 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 heat exchanger of tuna is a network of subcutaneous vessels that supply blood to the lateral muscles, where main role assigned to the red muscles ( muscle fibers special structure adjacent to the spinal column).
The vessels that irrigate the red lateral muscles with blood form an intricate pattern of intertwined veins and arteries through which blood flows in opposite directions. The venous blood of tuna (warmed 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 person to notice and describe this morphological feature genus Thunnus, became the Japanese researcher K. Kisinuye. He proposed to allocate all the tuna into an independent detachment, but, unfortunately, he did not receive support from his colleagues.
Behavior and lifestyle
Tunas are considered social animals, characterized by school behavior - they gather in large communities and hunt in groups. In search of food, these pelagic fish are ready to make throws over maximum distances, especially since they can always count on their staying talents.
When preparing to hunt, tuna line up in a curved line (similar to the string of a drawn 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 them threatens with death, since the respiratory process is triggered by the transverse bending of the body coming from the caudal fin. Moving forward also ensures a continuous flow of water through open mouth into the gills.
Lifespan
The lifespan of these amazing ocean inhabitants depends on the species - the more massive its representatives, the more longer life. The list of long-lived tuna includes common tuna (35–50 years), Australian tuna (20–40 years) and Pacific bluefin tuna (15–26 years). The ones that linger the least in this world are yellowfin (5–9) and mackerel tuna (5 years).
Range, habitats
Tunas somewhat distanced themselves from other mackerel over 40 million years ago, settling throughout the World Ocean (with the exception of the polar seas).
This is interesting! Already in the Stone Age, detailed images of fish appeared in the caves of Sicily, and in the Bronze and Iron Ages, fishermen of the Mediterranean (Greeks, Phoenicians, Romans, Turks and Moroccans) counted the days until tuna came to spawn.
Not so long ago, the range of common tuna was extremely wide and covered the entire Atlantic Ocean, starting from Canary Islands and ending North Sea, as well as Norway (where he swam in the summer). Bluefin tuna was a common resident 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 significantly narrowed. The habitat areas of small tuna are distributed as follows:
- southern tuna – subtropical waters southern hemisphere (New Zealand, South Africa, Tasmania and Uruguay);
- mackerel tuna – coastal areas of warm seas;
- Spotted Tuna - Indian Ocean and Western Pacific;
- Atlantic small tuna – Africa, America and the Mediterranean Sea;
- skipjack (skipjack tuna) - tropical and subtropical areas of the Pacific Ocean.
Diet, nutrition
Tuna, especially the largest ones (blue), eat almost everything that is in the depths of the sea - floating or lying on the bottom.
Suitable food for tuna are:
- schooling fish, including herring, mackerel, hake and pollock;
- flounder;
- squid and octopus;
- sardine and anchovy;
- small species of sharks;
- crustaceans, including crabs;
- cephalopods;
- sessile sponges.
Fishermen and ichthyologists easily recognize places where tuna deal with herring - its sparkling scales twist into funnels, which gradually lose speed and slowly dissolve. And only individual scales that did not have time to sink to the bottom remind us that tuna recently dined here.
Tuna breeding
Previously, ichthyologists were confident that the depths of the North Atlantic were inhabited by two schools of common tuna - one living in the Western Atlantic and spawning in the Gulf of Mexico, and the second living in the Eastern Atlantic, going to spawn in the Mediterranean Sea.
Important! It was from this hypothesis that the International Commission for the Conservation of Atlantic Tuna proceeded, setting quotas for its catch. Fish production was limited in the Western Atlantic, but allowed (in larger quantities) in the Eastern Atlantic.
Over time, the thesis about 2 Atlantic stocks was recognized as incorrect, which was greatly facilitated by tagging of fish (which started in the middle of the last century) and the use of molecular genetic techniques. For more than 60 years, it has been possible to find out that tuna actually spawn in two sectors (the Gulf of Mexico and the Mediterranean Sea), but individual fish easily migrate from one place to another, and, therefore, the population is united.
Each zone has its own breeding season. In the Gulf of Mexico, tuna begin spawning from mid-April to June, when the water warms up to +22.6 +27.5 °C. Most tunas do not spawn for the first time until they are 12 years old, although puberty occurs at 8–10 years of age, when the fish grows up to 2 m. In the Mediterranean Sea, fertility occurs much earlier - upon reaching 3 years of age. Spawning itself occurs in the 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, each egg with a drop of fat hatches into a larva 1–1.5 cm tall. All larvae gather in schools on the surface of the water.
If you love sea fish, and especially tuna, then this article is definitely for you. In it we will tell you that tuna is not only tasty, but also healthy. We will also share some interesting recipes. True, we will not forget to warn you, since the meat of this fish also has some dangerous properties. But, fortunately, there are not so many of them.
Description and appearance
Tuna belongs to the mackerel family. This is a fairly large fish, some of its individuals grow up to 3-4 m in length and weigh 500-600 kg. Although, in principle, the sizes of these representatives of the family can vary noticeably. There are fish “only” 50 cm long and up to 2 kg in weight. Tuna is a predator with a spindle-shaped body narrowed towards the tail. The caudal stalk is “equipped” with a large leathery keel. 
The dorsal fin is shaped like a sickle, which helps in fast and long swimming. This fish is an excellent swimmer, it can accelerate to 90 km/h. Chasing prey, she covers enormous distances without any problems. The main food for her is her smaller brother - sardine, mackerel, and also crustaceans and mollusks.
Habitat
Tuna is found in tropical and subtropical regions of the Pacific, Atlantic, and Indian oceans. But it can also be found in cooler temperate latitudes, for example, in the Black, Azov or Japanese Seas.
Did you know? The French called tuna "veal of the sea." The thing is that the color of the flesh of this fish is not pale, but bright red, like beef, since its meat contains the protein myoglobin, saturated with iron. By the way, once upon a time tuna was not very popular. It was first preserved only in 1903 in the USA. And this is only because there was a sharp decline in sardine catches. But over time, people fell in love with this sea fish and became really popular, which it still is today.
Species
There are about 50 varieties of tuna in nature, the most basic are:
Composition and calorie content
Tuna meat contains 95%, which is almost completely absorbed by the human body. Fish also contains essential amino acids and a minimum of fat and calories. It is called a dietary product, because 100 g of tuna “stores” only 100 kcal. Therefore, this fish occupies an extremely important place in the diet of athletes. Tuna contains substances that make hair and skin look beautiful and well-groomed - and the latter also activates metabolism. In it you will find almost a complete set of vitamins, and not only them.
Important! Tuna is similar in appearance, taste and even chemical composition to animal meat. That's why this fish will be an excellent option for those who, for some reason, need to stop eating meat.
Useful and healing properties
About the beauty of skin and hair, which tuna helps achieve, and about its dietary properties you already know. Now let's talk about the other most useful properties of this inhabitant of the deep sea:
- has a beneficial effect on the system, helps breakdown and normalizes blood circulation;
- helps get rid of skin diseases and other allergic skin rashes;
- tuna has no carbohydrates (only if it is cooked without oil), which makes it healthy for diabetics;
- by eating this fish, you, without knowing it, are preventing cancer, since the enzymes contained in it suppress the activity of free radicals that activate the development of tumors;
- People are advised to eat tuna when they have disorders, as well as;
- removes toxins from the liver, normalizes the production of useful enzymes in it;
- helps overcome high blood pressure;
- protects the bones of old people from osteoporosis and other ailments of the skeletal system;
- helps curb the aging process, helps strengthen the immune system, normalizes metabolism;
- normalizes the reproductive sphere;
- provides positive influence to work.
Did you know? Tuna dishes are an integral part of the diet of students and researchers at Harvard and Berkeley. This fish is certainly present in their menu for productive brain function.
Canned: selection criteria
What you should pay attention to when buying canned tuna:
- First, look at a canned food jar. It is good if there are no side seams on it, since rust appears in these places or the metal oxidizes. Do not take a deformed jar; pressure is redistributed inside such a tin, which has a detrimental effect on its contents.
- The production date is usually squeezed out from the inside of the jar. It must also contain an assortment mark, shift number, and the fishing industry index - the letter R. The marking made with paint must be durable and not wipe off even when exposed to moisture.
- It takes about 3 months for the fish to release its juices and acquire the most delicate taste. It is better to take a jar with a production date - about 3 months ago.
- Shake the jar: if there is a lot of liquid inside, then there will be few fish there.
- If the tin says “albacore”, this indicates that this is definitely tuna and not a fake. You remember that albacore is the most valuable variety.
- Please note the manufacturer. In terms of quality, Japan, Italy, and Spain share the championship here. True, here you can more often find canned food from Thailand and Seychelles, where they often skimp on quality. If you see canned food made in the Russian Federation, they are 100% frozen fish.
- Having already opened the jar, examine the meat itself. Tuna is quite large in size, and conscientious producers place it in a container in one piece. This is meat with large fibers, without bones. If there are a couple of pieces in the jar or the fish is flaking, then you have either low-quality tuna or not it at all.
Dangerous properties of meat
Despite all its usefulness, tuna also has dangerous properties. For example, it is better not to eat meat very major representatives this fish, because over their long life they often accumulate heavy metals. Tuna is contraindicated for women carrying or nursing a child, and small children (less than three years old). And, of course, allergy sufferers and people with individual intolerance to the product should not eat this fish. They say that it should not be eaten by those who suffer from kidney failure. But here it is better to consult with your doctor.
How to cook
Despite the fact that tuna is a fatty fish, after being on the fire for too long, it begins to dry out. So when cooking, keep this point in mind. If you don’t know what to cook from tuna fillet, here are some simple recipes.
Baked Tuna:
Preheat the oven to 220 degrees. Grease a baking sheet with vegetable oil. Cut the fish into steaks, each 2.5 cm thick. Place them in a mold, sprinkle with spices, and grease the top with pre-melted butter. Bake for 7-10 minutes.
Fried:
Heat a frying pan with three tablespoons on the stove. Rinse the fillet under water and let it drain. For better taste the fish can be breaded in whipped and white-black. Fry each fillet on both sides over medium heat for no more than 12 minutes.
Marinated:
Cut the fillet into slices 2 cm thick and place in a container. Make the marinade. If based on 300 g of fillet, then 30 ml of soy sauce and 30 ml of white wine will be enough. Lightly rub the fish with salt and place in the marinade for a day. To ensure that the fillet marinates evenly, turn it 2-3 times during this time. At the end, drain the marinade and dry the slices. Serve with olive oil. If desired, you can sprinkle a little lemon juice before serving. You can also make canned tuna at home. There is nothing supernatural about this.
Homemade canned tuna:
- tuna - 1 piece;
- salt - 1 tablespoon;
- vegetable oil - 100 ml;
- black pepper (peas), bay leaf - 8-10 pieces each;
- parchment, baking sleeve.
Canned tuna in olive oil:
- olive oil;
- black pepper (peas);
- jars with lids.
Close the jars, lower them into a wide container, placing a cloth or wooden grid on the bottom, pour cold water so that it does not reach the edges of the jars. Cover with something on top and sterilize for at least 1 hour from the moment of boiling. Cool the jars without removing them from the container or removing the lids at all. That's it, the product is ready.
Did you know? In the capital of Japan, Tokyo, there is a traditional annual tuna auction. Several years ago, the owners of the Kiyomura Co sushi restaurant chain set a record at this auction, paying $728.1 thousand for one fish. The weight of the sold lot increased by 269 kg. It’s even scary to imagine how much sushi from this fish later cost visitors to the restaurant chain!
Now you know not only about all the beneficial properties of tuna, but also have several delicious and uncomplicated recipes in your arsenal. For lovers of sea fish, they will definitely come in handy. Most importantly, do not forget about contraindications!
The water spaces of our planet are inhabited by about 20 thousand species of fish. The vast majority of them are marine fish (more than 14.5 thousand species). Anthropogenic impact on the inhabitants of the seas and oceans affects much less, therefore, according to sanitary and hygienic criteria, sea fish is considered much “cleaner” than freshwater fish.
Description of tuna
The largest tuna in the world, caught in 2012 off the coast of New Zealand by a spin fisherman, weighed 335 kg.
Life of this kind mackerel fish due to anatomical features it is impossible without constant movement, to which they are perfectly adapted. Tuna has a spindle-shaped body with massive lateral muscles, narrowing towards the tail. The tail stem is equipped with a large leathery keel; the back fin has a sickle shape ideal for fast and long swimming. The blood is saturated with oxygen, and the body temperature is much warmer than the water, which allows them to feel comfortable in cold water bodies.
The fish is widespread in the tropical and subtropical regions of the Pacific, Atlantic and Indian oceans, but is also found in cooler temperate latitudes: it lives in the Black, Japanese, Seas of Azov. A subspecies of Atlantic bluefin tuna is found in the Barents Sea.
Tunas are excellent swimmers, capable of reaching speeds of up to 90 km/h. In pursuit of food, they are able to quickly overcome vast spaces. Tuna stay in large schools. The red color of the meat is explained by the presence of the iron-containing protein myoglobin, which is actively produced in the muscles during “high-speed” movement.
The main food for tuna is small fish (sardine, mackerel, herring), crustaceans and mollusks. The ability to reproduce in tuna begins at the age of three. A large female is capable of laying several million eggs. Spawning occurs in warm subtropical waters in June-July.
Types of tuna
There are about 50 species and subspecies, but several of them are considered the most famous:
- Common or red tuna is distributed in the equatorial waters of the Atlantic Ocean, the Caribbean and Mediterranean Seas, the northeastern regions of the Indian Ocean, and the Gulf of Mexico. Red tuna is also occasionally found in cooler latitudes: off the coast of Greenland and in the Barents Sea. The largest tuna of this species weighed 684 kg, with a length of 4.58 m.
- Atlantic or blackfin (also known as blackfin tuna) is the smallest tuna. Adult specimens grow no more than one meter and gain Weight Limit– 20 kg. The lifespan of this species is the shortest among tunas - about 4-6 years. Atlantic tuna has yellowish sides and a back fin with a yellow tint. This species is preferred only warm seas Western Atlantic (from the coast of Brazil to Cape Cod).
- Bluefin tuna is the largest species. Maximum length – 4.6 m, weight – 680 kg. Its thick body is circular in cross section. Large scales along the lateral line resemble a kind of shell. The habitat of bluefin tuna is very wide - from tropical to polar waters of the world's oceans. Bluefin tuna is of greatest commercial importance.
- Yellowfin tuna (aka yellowtail) lives in tropical and temperate latitudes, with the exception of the Mediterranean Sea. Maximum length – 2.4 m, maximum weight – 200 kg. The hind fins of these fish are bright yellow in color. An adult yellowtail tuna has 20 vertical stripes on its silvery belly.
- Albacore, longfin or white tuna is famous for the most tender and fatty meat. Longfin tuna weighs about 20 kg. Distributed in temperate and tropical latitudes of the world's oceans. White tuna meat is considered the most valuable.
Yellowtail tuna
This type of fish (they are also called yellowfin tuna) is so called because of the special coloring of the dorsal (soft) and anal fins. They look orange-yellow.
The largest individuals can grow up to 2 meters in length and gain a weight of 130 kg. The growth process of tuna is very intensive; the rate of increase in length is 50...60 cm annually. In 2 years, the fish reach a weight of 13 kg, after 4 years - 60 kg.
Yellowtail tuna lives only in warm waters and is found in all the earth's oceans. The distribution area is limited to the border with a water temperature of 20 degrees. When the indicator drops to +18°C, this type of fish is almost impossible to find in such a region. It is caught in the waters of the Mediterranean Sea, and locals consider it their Mediterranean tuna and prepare excellent dishes from it.
Adult individuals live only in the oceans, in open spaces, at depths of one and a half hundred meters. The young stay in flocks, constantly closer to the surface and to the shore. In the tropics, yellowtail tuna are found everywhere, but their number depends on the condition. food base. There are more fish in waters where there is increased biological productivity and a lot of food.
Within the territory of one habitat, tunas often form numerous populations that live in certain areas of the oceans. Among them there are those who make long migrations. There are others who prefer local waters and settled life. Yellowfin tuna do not make Pacific movements, like some of their counterparts (bluefin tuna, albacore).
Yellowtail tuna, like its relative the common tuna, is indiscriminate in food and does not have any preferences. The fish feeds everywhere on any organisms that it encounters along its travel route. This is confirmed by the composition of food residues in the stomachs of caught individuals, which contain up to 50 different fish belonging to different groups.
Small tuna, whose life is spent near the surface, hunt more for fish, for which the layers of water near the surface are their “home”. Large ones prefer to eat gempilas, sunfishes, sea breams, whose habitat is mid-depth.
The ability to have offspring in yellowtails or, as they are called among professional fishermen, yellow tunas appears only when they grow 50...60 cm in length. The number of eggs varies among individuals of different sizes. The minimum is approximately 1 million pieces, the maximum is 8.5 million pieces. The spawning period of yellowtail tuna in the tropics is all seasons of the year, closer to the boundaries of their habitat in the summer.
Longfin tuna
Such fish are also called albacore. It differs from other species by the fins located on the chest, which are large in size.
You can meet individuals from this species in the oceans, in their free spaces. The most promising places for this are between the forties latitudes. They approach the coastal areas of reservoirs extremely rarely. Only 2–6-year-old fish can live outside the boundaries of their range. And only in the upper layers, if they are sufficiently warmed by the sun. Fish can only tolerate the salinity inherent in ocean waters. Reliably withstand temperature fluctuations in the range of +12°С…+23°С). At the same time, with low salinity levels, freshwater tuna is an unreal phenomenon and not found anywhere in the world.
In the first years of life, fish are in the surface layers of water. When they reach sexual maturity, they “go” to 150...200 meter depths and into the tropics of the Earth.
Fish that have “mastered” moderately heated waters and live there, feed mainly on inhabitants (crustaceans, fish, squids) living in layers of water close to the surface of reservoirs. In the tropics, her food contains deep sea inhabitants(sea breams, gempilas, some cephalopods).
Longfin tuna reaches the period of sexual maturity after 4...5 years of life. Its condition is characterized by almost a meter (90 cm) length and 45 kg of weight. Spawning in the tropics occurs in spring-summer period, at the boundaries of the zone. Females lay up to 2.5 million eggs.
Fish are characterized by constant migration, and over considerable distances. For example, in Pacific Ocean This is observed between Japan and the shores of America almost all the time along the same routes.
Today longfin tuna is protected by the international Red Book.
Black tuna
This species is the smallest known. Usually it does not exceed half a meter in length and 3 kg in weight. Although occasionally individuals are observed that are a meter long and weigh more than 21 kg.
The habitat of black tuna is very limited, which makes it stand out among its fellows. It is found only in the Atlantic, and in its western part. This is the area south of Rio de Janeiro and north of Massachusetts. For life, it prefers near-surface places where the water is clean and warm.
The fish's body is close to an oval in shape. It, together with the tail (has a crescent-shaped profile), allows the black tuna to move at very high speed. The body of the fish is painted white on the belly, silver on the sides, and the color of the back can be black, bluish-gray or an intermediate shade. There is also a stripe on the sides with blurred boundaries and a golden-yellow color. It is wide at the head and narrow at the tail. There are small protrusions on the body below (tail-anal fin section) and above (tail-second dorsal fin section).
This wild tuna becomes sexually mature faster than all its relatives - by 2 years. Spawning occurs in different places Habitats vary from April to November. The fry appear quickly and immediately begin an independent life. They drift according to the will of the current in the water column, at approximately 50 meters depth. The fish grows quickly and by the age of 5 is considered old.
The diet of black tuna includes amphipods, crabs, shrimp, squid, and a variety of fish. Due to their small size, they themselves often become prey for other fish living in the oceans: skipjack tuna, large coryphaena, blue marlin.
Black tuna is prized by fishermen and is considered a coveted trophy.
Skipjack tuna
This species (also known as skipjack), unlike its relatives, has several longitudinal stripes located on the body. They have a silver color on their belly, and ash blue closer to the back. The fish among tunas, which constantly live in the open ocean, is the smallest. It is rarely caught, measuring a meter in size and weighing 25 kg. “Standard” with catch values of 5...3 kg and 60...50 cm.
Such tunas live only in the surface layers of water and only in the ocean. Sometimes it is caught offshore, but this is only possible near coral reefs. Habitat: Pacific Ocean, in its subtropical and tropical regions. Also lives in seas with warm (+17°С…+28°С) water.
It prefers to be in flocks, sometimes gathering in schools of up to tens of thousands of individuals. In a school there are often fish of the same age and physical condition, capable of moving equally quickly (speed reaches 45 km/h). In addition to “pure” ones, schools of fish mixed in composition (yellowfin tuna, dolphins) are less common.
Like most of their relatives, skipjack tunas undergo significant seasonal migrations. They are especially noticeable near the coast of Japan. In summer, concentrations of fish are observed here, sometimes as far as the Kuril Islands, to the south of which, at this time, bigeye tuna is found, living at great depths (over 200 m) and reaching 2.36 m in length.
Fish become capable of spawning after living for 2...3 years, when their body becomes 40 centimeters long. The fertility of fish is directly related to the latter. For example, females 40 cm long spawn up to 200 thousand pieces. eggs, 75 cm - up to 2 million pieces. The spawning areas coincide completely with the distribution areas of tuna and are found only in the tropics.
This species feeds on inhabitants of surface water bodies. Their diet usually includes big fish, crustaceans, squids. It includes more than 180 different animals. The specific set varies in each habitat.
Mackerel tuna
Fish of this species are the smallest of those living near the coast. It is an epipelagic fish, lives in the warm tropical seas of the Pacific, Indian, and Atlantic oceans.
The body color is dark blue on the back and almost black on the head. The sides are bluish with dark wavy stripes. The belly is white. The ventral and pectoral fins are of different colors: black on the inside and purple on the outside. The differences are the short length of the pectoral fins and the absence of a swim bladder.
It grows up to 40...30 cm and gains only 5...2.5 kg of weight. Sometimes you come across specimens 58 cm long.
The diet of these fish includes plankton and small fish (anchovies, silversides, etc.). Tunas themselves often become prey to their larger counterparts.
Puberty occurs when the body length reaches 35...30 cm. The fertility of females is 200 thousand...1.4 million eggs depending on the length of 30...44.2 cm. Fish spawn all year round: January-April in the Pacific Ocean (eastern part) ; August-April in Indian Ocean(southern part).
Mackerel tunas are prone to long migrations in ocean waters.
Atlantic tuna
Atlantic tuna is one of the brightest, fastest and largest fish. It is warm-blooded, which is very rare among fish. Lives in the waters of Iceland and the Gulf of Mexico. It appears in the tropical waters of the Mediterranean Sea, where it comes to spawn. This species previously lived in the Black Sea, but at present this population has remained in history.
The fish have a streamlined, torpedo-shaped body, which is ideally aerodynamic and allows the fish to move quickly and for a long time. The color of the back is metallic blue on top, the belly is silver-white, with a shimmering tint.
Atlantic tuna diet: zooplankton, crustaceans, eels, squid. The fish have an insatiable appetite, so they usually grow two meters in length and gain a weight of a quarter of a ton. There are also individuals with more impressive characteristics. For example, it is believed that the largest atlantic tuna was caught in waters near Nova Scotia. He “pulled” 680 kg.
Tuna fishing - features of fishing in the sea
Most often, schools stay at shallow depths, in places where small fish accumulate. Tuna hunt enthusiastically and noisily, so detecting their presence is not difficult due to the boiling white breakers and flying spray. Often schools of tuna are accompanied by dolphins and seabirds.
Usually the hunt begins with bait: in the intended area of its location, fresh or frozen bait is thrown overboard small fish. Tuna react very quickly to small bubbles of water, so fishermen widely use “artificial rain” as bait: a special sprinkler is installed at the stern of the boat, which waters the sea surface as the vessel moves, creating a bubble spot on it, which the fish confuse with a school feeding fry. Fishermen throw a spoon into the “bubble zone” at a vertical angle of 2-3 m and wait for a bite. This method is only good in calm, clear weather.
In other conditions, fishing is carried out by trolling: the bait (heavy spoon or wobbler with a depth of up to 5 m) is transported on a strong cord behind a floating vessel. A sea spinning rod is suitable as a tackle. The size of artificial baits should be quite large and bright - about 18 cm, otherwise the fish may simply not notice it, since fishing takes place from a boat moving at speed. The trolling reel and line should be strong (with a capacity of 50 to 130 lb).
Milk is hunted in places where it is widespread. The design of this fishing rod is simple: the basis is a durable fishing rod, which is used in conjunction with a special belt. The belt has a recess into which the butt of the rod rests when fishing for tuna. A strong cord or fishing line is tightly attached to the rod. The polished hook (No. 6/0) must be barbless. They throw it without bait - it works like a spoon.
The fish grabs the bait confidently and decisively, so hooking it is quite simple, but fishing for large trophies can take a long time: tuna is a strong and desperate fish that is capable of resisting for a long time and fiercely, testing the strength of the fisherman and his gear. Large specimens are removed from the water using hooks and special winches.
Useful and dangerous properties of tuna meat
The benefits of meat
Tuna is a unique product in which the beneficial qualities of fish are combined with the nutritional and taste properties of meat. This sea fish contains so many vitamins and phosphorus that the leadership of American universities has introduced tuna dishes into the mandatory menu of the dining halls, in order to maintain the mental activity of students and teachers. French nutritionists compare the meat of this fish with young veal in terms of hemoglobin levels and protein content. But unlike beef, the proteins that tuna is so rich in are very quickly and almost completely (95%) absorbed by the body. Dutch scientists have confirmed the fact that consuming just 30 g of this fish per day can effectively prevent many cardiovascular diseases, thanks to the increased content of a natural complex of valuable fatty acids omega-3 and 6. Along with other vitamins, the composition contains valuable folic acid, which effectively reduces the level of the “evil” amino acid - homocysteine, which accumulates in the body with age and damages the walls of blood vessels.
The Japanese, the main consumers of this fish, are the most clear evidence of tuna's ability to preserve youth and prolong life.
Hazardous properties
However, tuna is harmful to small children and pregnant women - large individuals sea fish are able to accumulate mercury and lead in their organs over the years.
On the contrary, consuming fish meat prevents the occurrence of cancer and normalizes blood sugar and cholesterol levels.
Nutritional value and calorie content
Despite its record fat content, tuna is dietary fish. Depending on the type, nutritional value ranges from 110 to 150 kcal.
100 g includes:
- Proteins – 23.3–24.4 g;
- Fats – 4.6-4.8 g;
- Carbohydrates – 0 g;
- Ash – 1.2-1.7 g.
The lowest calorie species is the yellowfin (110 kcal). Even when fried, the energy indicator does not exceed 140 kcal. The calorie content of canned tuna in oil increases to 198 kcal.
Fish diet on tuna
Valuable composition and excellent taste qualities with low calorie content, tuna allows it to become the “king” of many dietary programs for health improvement and weight loss. Fish goes best with vegetables: cucumbers, lettuce, tomatoes, celery stalks, Chinese cabbage, bell peppers. Instead of mayonnaise, nutritionists recommend seasoning snacks and salads with tuna with olive oil. For diet canned tuna salad, it is better to use canned Tuna in own juice.
How to cook tuna: cooking recipes
Japanese chefs claim that this fish can be prepared with virtually no waste. Excellent broths and soups can be prepared from the head, some entrails and fins; steaks from large fish are very tasty fried and baked; famous toro and tuna sushi are prepared from the tender belly of fresh and fatty fish.
Unfortunately, fresh tuna is very rare, so a can for most of our fellow citizens is the most affordable option for including this very healthy and tasty fish in the diet. Fortunately, canned tuna almost does not lose the valuable properties of natural fish, and many interesting recipes from canned tuna allow you to enjoy a variety of dishes at any time. Pies, salads, cutlets, souffles and pates from canned food are prepared in a matter of minutes.
Niçoise salad with tuna (classic)
This salad is absolutely mysteriously popular in France. It would seem, how can a salad appear, the main ingredients of which are canned tuna and boiled eggs, in the “culinary Mecca”, a producing country and admirer of fresh natural products? However, Niçoise salad is on the menu of the vast majority of French restaurants.
Take a shallow dish. Lay its bottom beautifully with lettuce leaves, torn into several pieces. Then, in random order, add large slices of ripe tomatoes (3-4 pcs.), anchovies (6-8 fillets), green onions, basil (5-7 leaves), eggs cut into 4 parts (3 pcs.), canned tuna , disassembled into large fibers (1 jar). For the sauce: mix 40 ml olive oil, one clove of chopped garlic, salt, 1.5 tsp. wine vinegar.
Tuna pate
Mix 1 tbsp in a blender. thick yogurt, cream cheese (100 g), zest from half a lemon, a pinch of ground paprika and a jar of canned tuna in oil. You can add capers to the resulting homogeneous mass. This pate is especially delicious with bagels or sesame buns.
Cutlets
To prepare 10 cutlets, mix 1 jar of fish in its own juice (the juice must be drained), 1 glass of well-cooked rice, half a glass of wheat flour, a spoonful of mayonnaise, one egg, salt, 50 g grated cheese, a spoonful of chili sauce, one large boiled potato, a few cloves of chopped garlic. The minced meat should be kneaded well and formed into 10 cutlets.
Fry the cutlets until a delicious crust forms on both sides.
Seared Tuna Recipe
To experience the unique taste of tuna, it is very important not to dry it out when frying, otherwise, instead of a delicacy, you may end up with a tasteless and tough piece of fish. Ideally suited for frying are portioned steaks frozen directly on the boat, which are thawed immediately before cooking.
Mix salt, black and red pepper in equal parts in a cup. Rub the pieces of fish well with this spicy mixture, then roll in fine flour, and then in semolina. Such thorough breading will preserve the precious tuna juice. Fry the steaks in oil for no more than 2 minutes on each side. The center of the steak should still be slightly raw and pink. Serve fried tuna with salsa or tartar sauce with a side dish of any vegetables and a glass of good wine.
Tuna photo
Catching this fish is characterized by maximum excitement and impressive trophies. Tuna is a solid, beautiful, strong fish, and defeating it in a worthy fight is a matter of special pride for a fisherman. The photo gallery presented here will to some extent help you appreciate the beauty of hunting for the main “gladiators” of the seas.
Tuna fishing, video
The video shows the final stage of a duel between a fisherman and a bluefin tuna. The fisherman has already taken a position and has begun to fish for fish in the fighting chair; the gear has been thrown from the side of the vessel and securely secured in the glass of the chair. Not the largest specimen for this type of tuna, it bends a powerful fishing rod with incredible strength and tests the strength of the reel brakes with unimaginable maneuvers. No wonder it's blue tuna For their excellent fighting qualities they are considered the strongest and bravest fish!
If earlier tourists came to Cyprus to swim and sunbathe between shopping and going to restaurants, now more and more people want to do sea fishing on a yacht. Tuna fishing in the open sea is especially popular among guests. The video shows one of these flights, which culminated in the capture of five medium-sized tuna by lane fishing. The very first tuna was eaten by satisfied fishermen right on the yacht, in the form of sashimi with soy sauce.
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Tuna is one of the most valuable commercial fish, a close relative of mackerel, and has an exquisite taste.
It is called “calf of the sea” or “chicken of the sea” for its atypical taste for fish.
Mackerel are active swimmers; their muscles contain a large amount of myoglobin, which gives the product its unusual color.
Our publication is about the dangers and benefits of tuna meat for the body of men, women and children, composition and calorie content per 100 g, contraindications, methods of preparing fish.
How to choose a quality product
Tuna is sold fresh, frozen or canned.. The shelf life of fresh and frozen products is limited: fresh fillets are stored for no more than 4 days, frozen fillets are stored for up to 2 weeks.
Fresh tuna fillets are similar in color to beef. Questionable freshness is indicated by the uneven shade of the piece you like.
It's even worse if brownish spots are visible on it.
When choosing a packaged product, you need to carefully study the information on the packaging, best before date. The best time for such purchases is May-August.
Canned tuna is more accessible - in its own juice or oil. Fish in its own juice retains more beneficial properties than fish canned in oil.
If we are talking about a dietary product, take into account that the addition of oil increases the calorie content of the product.
When choosing canned food carefully inspect the packaging. Cans that are deformed, swollen, or with traces of rust do not deserve your attention.
Then study the markings and information on the label. The marking can be embossed from the inside or applied with permanent paint.
Fuzzy symbols and poor quality paint are indicative signs that the canned food is not of the best quality. The most reliable marking is a convex marking, since it is applied in production, and counterfeiting becomes impossible.
In the first row of characters the assortment code is indicated; for tuna it will be the abbreviation GTN. In the second row of characters the date of manufacture is indicated.
It is better to take a product released more than 3 months ago. During this time, canned tuna acquires a rich taste.
In addition, it makes sense to shake the jar and roughly assess the ratio of fish to liquid.
Canned tuna contains only fish meat, salt and vegetable oil if you choose canned food with added oil. Products in their own juice retain more beneficial properties and taste richer.
In addition, canned food in oil has another pitfall- some manufacturers alternate old and young specimens, and the oil masks the differences in taste.
There are also ethical restrictions. When choosing canned products, it is advisable to look for those that have the “dolphinfriendly” mark on the label.
This means that the fishing was carried out legally, without violating technology and did not lead to the death of dolphins.
Tips for choosing canned tuna:
Chemical composition, nutritional and energy value
Is tuna harmful or beneficial? Fish is in great demand, this is not at all surprising. The meat of these giant mackerel contains a large number of useful substances: from essential amino acids to a rich complex of microelements.
It contains, manganese, and sodium.
In addition to microelements, vitamins were found in tuna(calculated per 100 g of product):
Tuna contains a small amount of fat, which includes polyunsaturated fatty acids Omega-3 and Omega-6. These compounds support normal blood fluidity and the functioning of the cardiovascular system.
Polyunsaturated fatty acids improve vision, stimulate brain function, and support the functions of the reproductive system. The presence of Omega-3 and Omega-6 polyunsaturated fats helps strengthen skin, hair and nails.
There are no carbohydrates in tuna meat. Due to this feature, the product is considered low-calorie. Energy value– 139–145 kcal/100 g of product.
The calorie content of fish canned in its own juice is lower than that of a fresh product - about 110 kcal/100 g.
Glycemic index canned product – 96.
Useful properties
The beneficial properties of tuna meat are determined by its chemical composition. Polyunsaturated fatty acids Omega-3 and Omega-6 effectively lower the content of “bad” cholesterol in the blood.
This significantly reduces the risk of developing atherosclerosis and other cardiovascular diseases that develop due to circulatory disorders against the background of atherosclerotic lesions.
Eating 30 g of this fish daily reduces the risk of cardiovascular diseases (hypertension) approximately doubled.
With the systematic consumption of tuna, metabolic processes are normalized, which is especially important for people prone to allergic reactions and other diseases associated with disorders of plastic metabolism, and age-related changes slow down.
Tuna dishes are a useful addition to the diet for arthritis and other joint diseases. Substances with antioxidant activity protect cell membranes from the harmful effects of free radicals.
Oxidative processes are one of the key moments in the processes of aging and malignant degeneration of cells. That is, this fish is one of the effective means of prolonging youth and preventing cancer.
Antioxidants strengthen the immune system, increase the body's resistance to toxic influences.
The antitoxic effect of the product is determined by the presence of chromium and selenium - microelements that help cleanse the liver.
Chromium is involved in the regulation of carbohydrate metabolism. Phosphorus stimulates brain activity, strengthens muscles, and improves vision. Iodine is necessary for the prevention of thyroid diseases.
Unique B vitamin complex improves skin condition, stimulates regeneration processes. Tuna is useful for people with skin lesions of various origins.
Vitamin A is good for the retina, Vitamin E is needed for young couples planning to have children.
The beneficial properties of tuna will be revealed in the program “Food: Living and Dead No.:
What are the health benefits?
During pregnancy
Is tuna good for expectant mothers? Contrary to expectations, consume this nutritious and healthy The product is not recommended during pregnancy and breastfeeding.
During pregnancy, women experience transient kidney problems. The high protein content in food turns from an undoubted advantage into an undoubted disadvantage.
In uncomplicated pregnancy, tuna can be included in the diet, but in very limited quantities - no more than 200 g per day and no more than twice a week.
Before making a final decision regarding this delicacy, you should consult your doctor.
For children
This fish is included in children's diets only after 3 years. due to potential mercury hazards. For older children, tuna can be given according to the recommended age allowances.
This product promotes normal harmonious development mental and physical abilities of the baby.
Complete animal protein fully covers the needs of a growing body for essential amino acids.
One serving contains approximately half the daily value of vitamins group B.
Phosphorus, calcium and vitamin D contribute to normal skeletal development, iodine is necessary for the development of intelligence.
For the elderly
In old age, products that inhibit the development of cardiovascular and other diseases come to the fore. Tuna is famous for its ability to normalize metabolic processes - carbohydrate and lipid metabolism.
Consuming this delicious product slows down the progression of atherosclerosis, reduces the likelihood of cancer processes.
Thanks to the rich content of vitamins and microelements, the product slows down age-related changes in cartilage tissue.
Vitamin D combined with calcium and phosphorus in an easily digestible form– an almost ideal means of preventing osteoporosis.
Potential danger, contraindications
Any product that is consumed in moderation can cause harm. There are categories of people for whom tuna is not recommended or contraindicated.
These are pregnant women, nursing mothers and children under 3 years of age. Why is tuna harmful?
Because this fish accumulates mercury in its tissues, it is better to avoid using it. If expectant mothers can occasionally enjoy this delicacy, small children are introduced to it only at 4 years of age.
High protein content may harm people with kidney disease. Dishes made from tuna meat are contraindicated in cases of severe renal failure. Restrictions may also be imposed for other kidney diseases.
The “Live Healthy!” program will tell you how tuna can be dangerous:
How much and how to eat
We are more familiar with dishes in which the fish undergoes preliminary heat treatment. Tuna can be boiled, fried, baked, canned food is used to make salads.
The daily intake of fish for adults is about 50 g per day, but not more than 360 g per week. Nutritionists recommend serving it at least twice a week, for older people - up to 4 times.
Tuna is a dietary product, it is included in therapeutic and preventive diets recommended for cardiovascular and some other diseases.
This is the ideal product for sports nutrition and correction of body weight.
Tuna salad with grapes. To prepare you will need tuna fillet (400 g), yogurt (150 g), a bunch of grapes, a glass of walnuts, 1 lemon.
Sprinkle the fish with grated zest and bake in the oven at 180 degrees for 20 minutes. Grind the finished fillet with a fork so that small pieces remain.
Lightly fry the nuts, chop, mix with halved grapes, mix with unsweetened yogurt. Add chopped fish, mix, transfer to a salad bowl, garnish with lemon zest and grapes.
Stuffed tuna. For cooking you will need: tuna carcass (2-2.5 kg), one onion (300 g), butter(170 g), 6 tbsp. l. vegetable oil, (400 g), salt, bay leaf, spices.
Wash the fish, carefully remove the skin, remove the bones and cut. Grate the carrots and tomatoes, finely chop the onion. Fry onions and carrots separately in vegetable oil.
Melt butter and combine with carrots. Mix about a third of carrots and onions with grated tomatoes, bring to a boil, add salt, spices and bay leaves.
Pass the fish through a meat grinder, mix with onions and carrots, add salt and spices to taste. Wash the skin and stuff it.
Pour the prepared tomato sauce, put the fish and pour the sauce over it. Bake in the oven for an hour, occasionally basting with sauce. Baking temperature – 180 degrees.
Tuna steak, video recipe:
Tuna - a generous gift of nature, the perfect combination of business and pleasure. It deserves to become a harmonious addition to your menu.
Tuna is a genus of fish from the mackerel family.
They are perfectly adapted to their way of life consisting of tireless movement. Their body is dense and torpedo-shaped. The dorsal fin is sickle-shaped and is ideal for long and fast swimming at speeds of up to 77 km/h. This fish sometimes reaches 3.5 m in length.
Tuna live in large schools and travel long distances in search of food.
Tuna is widespread in tropical and subtropical regions of all oceans and everywhere adheres to fairly large depths (up to 200 m or more). Only young individuals of this species live near the surface, forming rather dense flocks. Adult fish probably lead a solitary lifestyle. Tuna breeding occurs in tropical zone and continues throughout the year. Its fertility varies from 2.9 to 6.3 million eggs. Tuna feeds on a wide variety of animals. Especially great value They eat deep-sea and semi-deep-sea fish - crabbills, alepisaurs, godwit, hempilidae, as well as squid, pelagic octopuses, and large shrimp.
One of their unusual characteristics is that the energy expended in moving quickly makes their blood several degrees warmer than the surrounding water.
In the world market it ranks second among all aquatic products after shrimp.
Useful properties of tuna
Tuna meat has the highest protein content among all fish - 22..26%. In this respect, it can only be equated with the caviar of some species of commercial fish. The fat content of meat ranges from a fraction of a percent to 19%.
Tuna meat contains such micro and macroelements as: calcium, magnesium, sodium, potassium, phosphorus, chlorine, sulfur, iodine, iron, zinc, copper, manganese, fluorine, chromium, nickel, cobalt, molybdenum; as well as vitamin B1, B2, B6, B9, PP.
Tuna meat contains all the amino acids necessary for the human body.
Young albacore and bluefin tuna contain unique omega-3 fats that can help cut your risk of heart disease in half. In addition, omega-3 complex (linoleic, eixapentinoic and doxaexinoic fatty acids) improves eye and brain function, reduces arthritic pain, has anti-inflammatory effects, promotes weight loss and even reduces the risk of certain cancers. Moreover, to achieve a preventive effect, 5.5 grams of omega-3 fats per month is sufficient (which corresponds to 1 can of albacore in its own juice per week).
Tuna meat is good for the skin and mucous membranes, nervous and digestive systems, regulates blood sugar and exhibits antioxidant properties.