Sturgeon and Beluga in particular, are highly valuable commercial species. However, due to the sharp reduction of the number of natural populations in the second half of the twentieth century to the present time, the fish, the Beluga is listed in the Red book as a rare species. However, it can be grown in artificial conditions, although with certain difficulties. Beluga caviar is the most expensive caviar in the world.
White sturgeon is a migratory fish, there are lives in the sea, but spawns in the river. This species inhabits the Caspian, Azov and Black seas.
The most numerous is the population of Caspian Beluga in the sea it can be found everywhere. The main spawning site for Beluga of the Caspian is the Volga. Also a small number of these fish are spawning in the Ural river, Kura and Terek. Very very tiny number of spawns in small rivers flowing into the Caspian sea in Azerbaijan and Iran. But in General, it can be found in any river, quite close to the places of the Caspian sea, where the fish is the Beluga.
In the past, spawning Beluga came into the river far enough for hundreds and even thousands of kilometers. For example, on the Volga, she rose to Tver and to the upper reaches of the Kama. However, due to the construction of numerous hydroelectric power stations on the rivers flowing into the Caspian sea, modern belugas must be limited to only the lower reaches.
Previously, numerous enough were the Azov population of belugas, but to date, she was on the verge of extinction. From the sea of Azov fish rises in the dawn and in very small quantities in the river Kuban. As in the case of the Caspian sturgeon natural spawning grounds high in the flow was cut off by the construction of hydroelectric power plants.
Finally, in the Black sea, where the fish lives Beluga, its population is also very sparse and concentrated mainly in the North-West of the sea, although recorded case of its occurrence off the coast of the southern Crimea, the Caucasus and Northern Turkey. Spawning local Beluga dressed in the three largest rivers are the Danube, Dnieper and Dniester. Some individuals spawn in the southern bug. Before the construction of hydropower plants on the Dnieper sturgeon caught in the area of Kiev, and even in Belarus. Similar situation with Dniester. But on the Danube, she still can climb far enough up to the Serbian-Romanian border, where one of the two Danube HPP.
To the 70-ies of the last century, the sturgeon is sometimes caught in the Adriatic sea, where she walked on in the river to spawn. However, in the last few decades no case of catch of Beluga in this region are not marked, causing the Adriatic sturgeon is considered to be extinct.
Beluga — description fish
Beluga sturgeon fish is the largest of all freshwater fish. In the historical Chronicles of the disputed authenticity of the mention of the catch of individuals of length up to 9 metres and weight up to 2 tons. However, those sources that are not questionable, the result is no less impressive figures.
For example, the book on the state of Russian fishery from 1861 mentions Beluga weighing 90 pounds (half a ton), caught near Astrakhan in 1827. Published in 1948, Handbook on freshwater fishes of the USSR mentions a female Beluga weighing 75 pounds (1,200 kg), which was caught in the Caspian sea near the mouth of the Volga river in 1922. Finally, everyone can personally see a stuffed Beluga solid, exhibited at the National Museum of the Republic of Tatarstan in Kazan.
The most recent case of catching such a massive specimens recorded in 1989, when the Volga Delta caught a sturgeon that weighed 966 pounds. Her effigy can also be seen in a Museum, but in Astrakhan.
According to experts, the biggest fish, the Beluga should be aged in decades. It is possible that some individuals could be aged 100 years or more. However, all this exceptional case. The average weight of fish spawning in the river is 90-120 kg in females and 60 to 90 kg in males. However, even of this size, the Beluga is only at the age of 25-30 years. And immature youngsters usually weighs no more than 20-30 kg.
If left alone the sheer size of this fish, in General it is typical for sturgeon appearance. She’s got a massive torso elongated cylindrical shape and a small sharp nose. Beluga has a blunt short snout and a large mouth in the shape of a Crescent. A mouth rimmed by a thick “lip”. On the snout there are a wide massive antennae.
The head and body dotted with symmetrical rows of bony scutes (also called bugs): 12-13 on the back, 40-45 on each side and 10-12 on the bottom. The dominant color in the color Beluga is grey, which is painted the back, sides, and top of the head. Bottom Beluga painted white.
The first thing mentioned in any description of fish, Beluga is her way to spawn. The main place of life of this fish are of the sea, but spawning it goes in large rivers, as mentioned earlier.
It is noteworthy that the Beluga has a so-called spring and winter forms (race). In particular, in the Volga fish comes in two waves: in the first half of autumn — winter, in the first half of spring — spring. However, dominates in this river all winter Beluga, which winters in river holes, and then immediately begins spawning in April-may. In the Ural river opposite the majority of belugas refers to the spring race, they spawn immediately after falling into the river, and then swim back into the sea.
Like all sturgeon, Beluga is a fish of prey. The young feeds on various invertebrates and clams, getting them on the bottom in estuaries. After at sea a grown young enough quickly goes to feeding fish. The Caspian sea is the basis of the diet of Beluga are carp, roach, sprat, etc. in addition Beluga had no qualms about eating their own young and other representatives of the sturgeon family. The black sea Beluga feeds mainly on anchovy and gobies.
Sexual maturity of Beluga reaches late: males at 12-14 years females — 16 to 18 minutes. Because of such a long maturation in conditions of intensive industrial fishing, the view and appeared on the verge of extinction.
As already mentioned, the spawning of sturgeon falls on the second half of the spring, although a significant part of the fish goes to the river in the fall. Spawning of Beluga when the spring flood peak, and the temperature of the river water is 6-7°C. Caviar is tossing on the rapids in the deep areas (not less than 4 feet, usually 10-12 m) with a rocky bottom. One female lays at least 200 thousand eggs, but usually the account goes on millions (8 million) of an Egg large enough in diameter approximately 4 mm.
After spawning, white sturgeon fish in the Volga and other rivers quickly went to sea. Young larvae also do not stay in the river.
Economic value of sturgeon
Since ancient times, is considered a commercial fish of high value. Active fishing is conducted at least since the VI century BC. In the XX century with the development of industrial fishing techniques, the production of sturgeon has reached unprecedented proportions. For example, in the Volga in 70-ies were caught annually by 1.2—1.5 thousand tons of this fish.
Unreasonably intense catch red fish white sturgeon, as well as the construction of hydroelectric power plants everywhere in the rivers, where it spawns, have led to a sharp reduction in its population during the second half of the last century. At the beginning of the 90s, the catch dropped to 200-300 tons per year, and at the end of the decade — below 100 tons. In such conditions the Russian government in 2000 banned the commercial catch of white sturgeon on its territory, a decade later, Russia joined other countries of the Caspian region. Things are even worse in the Black and Azov seas, where the population of Beluga has been reduced to miniscule size.
The actual inability to ensure supply of consumer meat market and, not least, the Beluga caviar has created the conditions for the development of fish farms that specialize in this type of fish. Today, they are the only legal suppliers of this product on the shelves. However, illegal fishing is, unfortunately, also holds a significant share of this market.
The fish factories Beluga divorce is not only and not so much in kind, how many’s hybrid with other sturgeon — sturgeon, stellate sturgeon and sturgeon. Especially large spread Bester — the fish is a cross between Beluga and sterlet. It is not only grown in fish farms, but even inhabit in the sea of Azov and freshwater reservoir.
Beluga in cooking
Meat Beluga and especially their eggs are considered a true delicacy, from which you can prepare true culinary masterpiece. The fish subjected to all types of heat treatment: boiled, fried, baked, steamed and grilled. And a sturgeon, smoked, knocked and canned. Meat Beluga is possible to prepare various types of dishes including kebabs and salads.
With all this in Beluga as the fish are very healthy. It has a low caloric value and high content of easily digestible protein. In the Beluga many essential amino acids, which are badly needed for our body, but not synthesized, and can only be obtained from food. The meat of this fish contains a lot of calcium and phosphorus, contributing to the restoration and strengthening of bones, and also improves the condition of nails and hair. Available in Beluga potassium improves cardiac muscle function and iron has beneficial effects on blood composition.
Beluga meat is rich in vitamin a, which affects visual acuity and the condition of the skin. It has other important vitamins (important for muscle and nerve tissue), D (prevents the development of rickets and osteoporosis).
We should also mention the Beluga caviar. The females spawn large black caviar, which is incredibly highly valued by gourmets. Since the commercial catch of white sturgeon is prohibited today, but in terms of aquaculture need about 15 years to grow fish to get away from her eggs, the cost of this product reaches sky-high prices. In Russia, 100 grams of Beluga caviar costs about 10-20 thousand rubles, pounds — to 150 thousand rubles. In Europe and other markets the cost of a kilogram of this caviar ranges from 7-10 thousand dollars. It is obvious that to buy in a regular store such eggs is unrealistic.
Artificial breeding of sturgeon
Beluga and Bester (fish of the sturgeon hybrid of Beluga and sterlet) can be fed with artificial feed, and therefore suitable for commercial fish farming. However, this technology is rather expensive, especially considering that to get the calves you want to raise fish for at least 15 years.
While the larvae do not reach the weight of 3 grams, grown in special trays. Meals both artificial and natural food. After reaching the larvae of the indicated weight, they are sent for rearing in ponds with a stocking density of about 20 thousand copies per hectare.
The technology to breed in the home fish Beluga provides for transfer of fingerlings to food fish meat of low value species with various additives. In parallel a significant part of the diet for youngsters will provide themselves at the expense of pond invertebrates. The instinct of the predator of fingerlings Beluga appears at the end of the summer, which implies a growth of the share of meat in her diet.
From Beluga fingerlings the weight gain is faster in conditions where temperature and composition of the water close to the optimal values, therefore, one of the most important tasks of the fishery is to maintain ponds for optimal conditions.
In the first year the average conversion rate of feed from Beluga is 2.8 units. At the end of the first season, the fish increases its mass from 3 to 150 g, With an average survival of fingerling at 50% of their fish productivity reaches 20 kg/ha.
In wintering ponds (optimal ponds ranging from a quarter to half a hectare at a depth of 2-3 m, and devoid of silt and vegetation) of fingerlings planted in the amount of 120 thousand pieces per hectare. Hibernation begins in October — November and lasts until March. In winter, the Beluga give feed in an amount of 2% of the total weight of the fish, and the formation of surface ice feeding is stopped altogether. For of fingerlings Beluga is a natural loss of 30-40% of its mass during this time. However, the dimensions of the Beluga sturgeon fish are not changed.
In early April, the fish sent back to grow-out ponds, where they apply intensive feeding. Dvuhletkami give low value frozen fish. Most of the young animals grow in the second half of the summer, and the conversion of the feed increases this period to 6 kg of feed per 1 kg increase in mass.
Upon reaching two years old mass of 0.7 kg (by the end of the second season about half) they are sent for sale to the food network. The rest of the fish leave for another year and grow to masses of 1.7—2 kg. In conditions of high survival rate of yearlings and three years old (95%) with strict observance of technology of growing fish productivity will be 50-75 kg/ha.