The Red Book is a living reminder to humanity ofhow thoughtless and wasteful it is with natural riches. Each species inscribed on its pages is a reason to think about the future of the Earth. Today, for example, the question of whether the unique large species of sturgeon fish - the Atlantic sturgeon - will remain on Earth is very acute. And once he was a frequent guest on the table at rich feasts and feasts.
Atlantic sturgeon - a chord of the class of ray-finned fish. It belongs to the numerous sturgeon family. Latin name of the species Acipenser sturio.
Inside the genus of sturgeon mind is given a special place.Phylogenetic relationships with other sturgeon species are not fully understood. There is a possibility of having a common ancestor with those species that have about 120 chromosomes (stellate sturgeon). Scientists have not yet established the exact taxonomic status for some populations that have fallen into geographic isolation. Most of the controversy surrounding the North American population of Atlantic sturgeon, which is trying to translate into species rank.
Sturgeon can be a walk-through, semi-walkthrough andfreshwater species. Two forms of Atlantic sturgeon live on the territory of the post-Soviet space: a migratory (anadromous) migrating into rivers and a freshwater (living) form that lives in Lake Ladoga.
In the old days, the giant Atlantic sturgeon inhabited the North and Baltic seas. Met along the shores of Europe in the Atlantic. Sometimes come across in the Black Sea. Species attributed to the valuable commercial fish.
Atlantic sturgeon during spawning migrationcan go into the waters of the Kaliningrad region, in the Gulf of Finland and even into the Neva. But constantly in these places he does not live. A single catch was recorded in the White Sea, a large individual caught near the mouth of the river. Umby. Passing species came across in the waters of the Northern Dvina.
Ladoga residential population has been little studied. It is known that Atlantic sturgeon spawns in the Volkhov River. Places spawning previously located at the bottom of the rapids.
The main feature of Atlantic sturgeon -giant sizes. Earlier, individuals whose body length exceeded 5 meters were encountered. Weight at the same time could exceed the limit of 600 kg. Sturgeons are recognized long-livers, and the Atlantic species is no exception. It is difficult for scientists to obtain accurate data on life expectancy, but individuals that fell into their hands were between 45 and 100 years old.
From fellow species Atlantic sturgeonit is distinguished by the absence of folds formed by the gill membranes below the interstitial gap. The mouth of the fish is small with an interrupted lower lip, the head tapers to the front and looks somewhat flattened. The role of the organ of touch is performed by two pairs of antennae. The eyes are also small, with a golden iris.
Like all representatives of cartilage ganoids,Atlantic sturgeon on the body are many longitudinal bone plates, called bugs. But it is in this species that their size is larger than the others. The tail stem is protected by large shields. On the back are rhombic bone plaques.
Color sturgeon dull. The body is olive-bluish, some individuals have a golden sheen. The bugs are painted lighter than the main body. The lower part of the body (belly) is white.
Проходные атлантические осетры мигрируют из моря in the river for spawning. They do not accumulate in large shoals, like other fish, but go alone or in small groups. By the time of reproduction there are spring and winter forms. Winter sturgeon remains to winter in freshwaters.
Juveniles live in rivers for several years. In the sea, young individuals leave, only having reached a certain body length (from 60 cm).
The age of puberty for the male comes onseventh-ninth year. The female matures later, to eight to fourteen years old (studies were conducted in the Black Sea). During spawning, the female can sweep several million eggs. Caviar is fixed on the substrate. Fetal development takes 3–4 days, but the water temperature should be around 20 ° C. At lower temperatures, embryonic development is delayed for 10-12 days. At the time of hatching the length of the larva is about 10 mm. In 2 weeks the body lengthens to 18 mm, at which time the larvae begin to feed on their own.
In the diet of larvae planktonic crustaceans andchironamides. They can be buried by insect larvae. Adult Atlantic sturgeons eat gerbils and anchovies, as well as invertebrate worms and small crustaceans. Sometimes there are shellfish in the diet.
Atlantic sturgeon on the verge of extinction.The number of individuals is very small, today the catch of the Atlantic sturgeon is prohibited throughout Europe. Therefore, it is difficult to say what the Atlantic sturgeon is caught on. Tackle is also hard to talk about. Only one thing is clear, if the numbers can be restored, and the catch of the Atlantic sturgeon will be possible, then it must be a very strong fishing rod with good tackle. Most often, the catch was made by gillnets during spawning migration.
In the old days came across a very largeAtlantic sturgeon. Trophy fishing, that is, the desire of fishermen to get the largest representative of the species, gave amazing results. Thus, in 1851, a female Atlantic sturgeon weighing almost 320 kg was caught. In addition to the delicious fillet, at that time the fishermen received 80 kg of caviar. In the Gulf of Finland, a large individual was caught in 1934. This fish weighed 177 kg. A significant trophy was also obtained in Lake Ladoga. The harvested Atlantic sturgeon was almost 3 meters long and weighed 130 kg. From the skin of this giant was made an effigy, which is stored in the Museum of the Academy of Sciences in St. Petersburg.
The last confirmed fact of prey Atlantic sturgeon occurred in 1984. A 1.5 m long female was caught, weighing about 30 kg.
Today it is confirmed that the Atlantic sturgeon is preserved in the Black Sea near the Rioni River.
Significant damage to Atlantic numberssturgeon causes human activity. Dams or dams are built on the rivers. For example, the Volkhov River, into which the Atlantic sturgeon spawns from Lake Ladoga, to spawn, in 1926 was blocked by a dam. In recent years, data on sturgeon in this river has not been reported.
Man dumps industrial into rivers and seassewage, water pollution affects the number of fish. The spawning grounds of sturgeon suffer from timber rafting. The trunks accumulate in separate areas, block the aisles and rot, disrupting the oxygen regime.
At the moment, scientists are puzzled by the cryopreservation of genomes to be able to recreate the species. These works will yield results only with the full cooperation of the countries concerned.
You can catch Atlantic sturgeon not only ontrophy fishing. Today there are online games where you can show your skills in the virtual world. Russian Fishing (RR) is a game that even a novice can easily figure out. On the Neva, the Atlantic sturgeon is caught in a special location called the Peter and Paul Fortress. Such fishing allows you to quickly pump levels in the game, without requiring additional costs.
Tips for beginners:
If you want to play in pp 3.7.(Neva), the Atlantic sturgeon must be caught by you necessarily. To do this, you need to spend about 2 million game rubles. The cost of Lock Fish is 450 thousand per 1 piece, while you need at least three. A good, powerful reel will cost at least 450 thousand. The bait can be bought or caught by yourself.
