Atlantic sturgeon: description, species and habitat

The Red Book is a living reminder to mankind of how thoughtless and wasteful it is of natural riches. Each species inscribed on its pages is an occasion to reflect on the future of the Earth. Today, for example, the question is very acute whether the unique large species of sturgeon will survive on Earth - the Atlantic sturgeon. And once he was a frequent guest on the table at rich feasts and feasts.

Description of the species

Sturgeon Atlantic - chordate from the class of radiant fish. It belongs to a large family of sturgeon. Latin name of the species Acipenser sturio.

Inside the genus of sturgeon, a special place is assigned to the species. Phylogenetic connections with other species of sturgeon have not been fully studied. There is a possibility of having a common ancestor with those species that have about 120 chromosomes (stellate sturgeon). Scientists have not yet established an accurate taxonomic status for some populations caught in geographical isolation. Most of the controversy surrounding the North American population of the Atlantic sturgeon, which is trying to translate into a species rank.

Types of Atlantic Sturgeon

Sturgeon can be a pass-through, semi-pass and freshwater species. Two forms of Atlantic sturgeon live on the territory of the post-Soviet space: anadromous (anadromous), migrating to rivers, and a freshwater (living) form that lives in Lake Ladoga.

Habitat

In the old days the giant Atlantic sturgeon inhabited the North and Baltic seas. Met along the shores of Europe in the Atlantic. Occasionally came across in the Black Sea. The species was referred to valuable commercial fish.

During spawning migration, the Atlantic sturgeon can enter the waters of the Kaliningrad region, the Gulf of Finland and even the Neva. But constantly in these places he does not live. A single catch in the White Sea was recorded, a large specimen was caught near the mouth of the river. Umba. Passage form came across in the waters of the Northern Dvina.

The Ladoga residential population has been studied little. It is known that Atlantic spawners go to the Volkhov River to spawn. The spawning grounds were previously located in the lower part to the rapids.

Appearance

The main feature of the Atlantic sturgeon is the giant size. Previously, there were individuals whose body length exceeded 5 meters. Weight at the same time could exceed 600 kg. Sturgeons are recognized long-livers, and the Atlantic look was no exception. It is difficult to obtain exact data on the life expectancy of scientists, but the individuals that fell into their hands were from 45 to 100 years old.

From the brethren of the genus, the Atlantic sturgeon is distinguished by the absence of folds formed by the gill membranes below the interbranchial gap. The mouth of the fish is small with an interrupted lower lip, the head narrows to the front and looks somewhat flattened. The role of the sense of touch is performed by two pairs of antennae. The eyes are also small, with a golden iris.

Like all members of the cartilaginous ganoid, in the Atlantic sturgeon there are a lot of longitudinal bone scutes on the body called bugs. But it is this species whose size is larger than others. The caudal peduncle is protected by large scutes. Rhombic bone plaques are located on the back.

Color of sturgeon is not bright. The body is olive-bluish, some of them have a golden ebb. Beetles are colored more lightly than the main body. The lower part of the body (belly) is white.

Features of behavior

Passing Atlantic sturgeons migrate from the sea to the rivers for spawning. They do not accumulate in large shoals like other fish, but go singly or in small groups. By the time of reproduction there are spring and winter forms. Winter sturgeons remain for the winter in fresh water bodies.

Young people live in the rivers for several years. In the sea, young individuals leave, only reaching a certain length of the body (from 60 cm).

Reproduction

The age of sexual maturity for a male comes in the seventh to ninth year. The female ripens later, to eight or fourteen years (studies were conducted in the Black Sea). During the spawning period, the female can sweep out several million eggs. Caviar is fixed on the substrate. Embryonic development takes place 3-4 days, but the water temperature should be about 20 ° C. At a lower temperature, embryonic development is prolonged by 10-12 days. At the time of hatching, the length of the larva is about 10 mm. For 2 weeks the body extends to 18 mm, at which time the larvae begin to feed independently.

What they eat

In the diet of larvae are planktonic crustaceans and chironamids. They can lick insect larvae. Adult Atlantic sturgeons eat gerbils and anchovies, as well as invertebrates of worms and small crustaceans. Sometimes in the diet there are shellfish.

Conservation status and fishing

Atlantic sturgeon on the verge of extinction. The number of individuals is very small, today the catch of Atlantic sturgeon is banned throughout Europe. Therefore, to say what the Atlantic sturgeon is caught is difficult. About gear, too, it's hard to say. Clearly only one, if the numbers can be restored, and the catch of Atlantic sturgeon will be possible, it must be a very strong rod with good tackle. Most of the catch was produced by gill nets during spawning migration.

In the old days there was a very large Atlantic 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 of Atlantic sturgeon weighing almost 320 kg was caught in the Neva. In addition to a delicious fillet, at that time the fishermen received 80 kg of caviar. In the Gulf of Finland, a large specimen was caught in 1934. This fish weighed 177 kg. A significant trophy was also received in Ladoga Lake. The caught Atlantic sturgeon was almost 3 m long and weighed 130 kg. From the skin of this giant was made a scarecrow, which is stored in the Museum of the Academy of Sciences in St. Petersburg.

The last confirmed fact of the production of Atlantic sturgeon occurred in 1984. The female was 1.5 m long, weighing about 30 kg.

Today it is confirmed that the Atlantic sturgeon is preserved in the Black Sea near the Rioni River.

Why the number decreases

A significant damage to the numbers of Atlantic sturgeon is caused by human activities. On the rivers dams or dams are erected. For example, the Volkhov River, into which the Atlantic sturgeon from the Ladoga Lake spawns, was rebuilt in 1926 by a dam. Over the past few years, no data on sturgeon in this river has been reported.

Man discharges industrial sewage into rivers and seas, the pollution of water affects the number of fish. The spawning grounds of sturgeons suffer from the felling of the forest. The trunks accumulate in separate areas, block the passages and rot, disrupting the oxygen regime.

At the moment, scientists are puzzled by the cryopreservation of genomes, so that there is an opportunity to recreate the species. These works will yield results only with the full cooperation of the countries concerned.

The game "Russian fishing"

You can catch Atlantic sturgeon not only on trophy fishing. Today there are online games where you can show your skills in the virtual world. "Russian fishing" (RR) is a game in which even a beginner can easily understand. On the Neva, the Atlantic sturgeon is caught in a special location, called the Peter and Paul Fortress. This fishing allows you to quickly pump the levels in the game, without requiring additional costs.

Tips for beginners:

• If you caught a large fish, drink alcohol and eat your ear.
• To catch a sturgeon is best on a float, so you can get more experience in the game.
• If you caught a small fry, drop it from the fishing rod.

If you want to play in PP 3.7. (Neva), the Atlantic sturgeon must be caught by you. To do this, you need to spend about 2 million game rubles. The cost of Lock Fish is 450 thousand for 1 piece, whereas you will need at least three. A good, powerful coil will cost a minimum of 450 thousand. You can buy the bait or catch it yourself.