Table of contents:
- Description
- Color
- Weight and length
- Spread
- Life span
- Nutrition
- Lifestyle
- Reproduction
- Puberty
- Development
- Economic value
Video: Atlantic Sturgeon (Acipenser Sturio)
2024 Author: Molly Page | [email protected]. Last modified: 2023-12-17 15:30
Atlantic sturgeon (European sea sturgeon) is an anadromous fish. Adult fish live in the sea, usually in coastal shallow waters, where they feed on benthic invertebrates, mainly molluscs and fish. Run into rivers is observed in spring, during floods. The maturation age differs in different parts of the range. For the ancient inhabitants of the Ladoga area, the sturgeon was an ordinary table fish. Perhaps this is due to its abundance at the beginning of our millennium, the ease and profitability of catching it: one fish immediately provided a lot of tasty nutritious food.
Photo © Johannes Pfleiderer
Description
The body of the Atlantic sturgeon is run-through, the snout is elongated and pointed. The bone ray (thorn) of the pectoral fin is very strong. Dorsal fin has 31-43 rays, anal 22-26. Dorsal beetles 9-15, lateral 24-36, abdominal 10-12. The bugs are very massive, more than 2 times larger than the bugs of the Russian sturgeon of the same size. Their surface is radially striated. Branchial stamens 18-25. The body between the dorsal and lateral rows of beetles is usually covered with several (up to 10-12) oblique rows of rhombic, densely set plates (sometimes there are no plates in young specimens). Beetles are sharply radially granular. The mouth is located under an elongated massive snout, on the flat underside of which there are four short antennae in front of the mouth. The lower lip is distinctly interrupted in the middle. The pectoral fin ray is strong. The stomach is soft, highly distended.
Color
The color is grayish-brown, darker from above, the belly is bright white, the eyes are with a yellow iris, relatively small for such a large fish. Very large specimens are golden green in color.
Weight and length
Atlantic sturgeon reaches 3 m in length and 200 kg in weight. The largest Baltic sturgeon was caught in the North Sea in 1904: it was 345 cm long and weighed 320 kg. In the Gulf of Finland, the largest sturgeon was recorded in 1934 at Repino: it was 280 cm long and weighed 177 kg; his age was about 22 years old. Lake Ladoga became famous for the giant caught in 1939: its length is 283 cm, it weighed 130 kg. A scarecrow of this specimen can be seen in the Zoological Museum in Leningrad.
Spread
The Atlantic sturgeon is an almost extinct species, previously widespread along the entire coast of Europe. The only representative of sturgeon fish in the basin of the Baltic and North Seas. Along the Atlantic coast of North America from Goodson's Bay to South Carolina. It enters the rivers Svir, Syas, Volkhov and Lake Ladoga. For sturgeons spawning in the tributaries of Lake Ladoga, this lake itself is, as it were, a sea (which it was in the Littorian time). In Europe, the Atlantic sturgeon is almost exterminated. In the Black Sea and in its basin it is known from the Danube delta, the southern coast of Crimea, the Caucasian coast, the Rion, the Anatolian coast, Burgas. Previously, he climbed the Rhine to Basel, along the Elbe - to Moldova, along the Oder - above Breslavl, along the Vistula - to Krakow.
Atlantic sturgeon begins to enter Rion at the end of April; high speed in May; thus, the entrance to the Rion is a month earlier than the Russian sturgeon and almost two months earlier than the stellate sturgeon. There is no autumn run to Rion, as well as for the Russian sturgeon. The age of the runner in Rion is at least 7-9 years in males, and in females at least 8-14 years. The average size of the running males is 137 cm, the females are 182 cm. In 1934, a female was caught 212 cm long and weighing 84 kg. Spawning grounds are located in the Samtredi area.
Life span
Up to 35-36 years old.
Nutrition
Sturgeon juveniles feed on benthic invertebrates (worms, molluscs, crustaceans), adults - mainly on small fish (anchovy). In pursuit of fish, it overcomes large areas. Food does not stop in winter.
Lifestyle
Atlantic sturgeon is an anadromous fish. In Lake Ladoga, the Atlantic sturgeon forms a residential form. Excavations carried out in 1911-1913 on the Volkhov near Staraya Ladoga, they found here, as MI Tikhiy's research showed, bones of a large number of large sturgeons; in a layer dating no later than VIII-IX centuries. AD, the remains of about 60 large sturgeon were found, ranging in length from 1.7 to 3.1 m, fish with a length of 2.1-2.8 m predominated; the age of some reached 35-36 years, and the average weight was 100-180 kg. Adult sturgeons make significant movements and can descend to a depth of 200 m.
Reproduction
Before spawning, the Atlantic sturgeon approaches the estuarine areas and lays down for the winter. Spawning temperatures vary greatly - from 7.7 to 22 ° C. In Volkhov, it spawns in June-July. In the rivers of the Baltic Sea, it breeds in June - July, in the rivers of the Black Sea - in May - June. Spawning grounds are located near the mouth. Caviar is sticky, bottom, deposited on stones and pebbles. Fertility varies, depending on the size of the females, from 200,000 to 5.7 million eggs. After spawning, the adults slide into the sea.
Puberty
In the Black Sea, males reach sexual maturity at the age of 7-9 years, females - 8-14 years. In the Leningrad region, for the first time, sturgeons go to spawn at the age of 12-15 years, females - 2-3 years later than males.
Development
The development of Atlantic sturgeon eggs lasts 3-13 days, depending on the temperature; fry quickly slide into the sea, where they live until puberty. After hatching, the larvae weigh on average 10 mg with a length of 8-11 mm. After resorption of the yolk at the age of 10-14 days with a length of 16-18 mm, the larvae switch to active feeding. The first downstream migrants begin to appear in the second half of May, the last ones - in the first days of July. The growth rate of the Atlantic sturgeon is faster than that of the Russian.
Economic value
Atlantic sturgeon is a very valuable but rare fish. Almost exterminated in the seas of Western Europe. In the late XIX - early XX centuries it was of commercial importance. The species is listed in the Red Data Books of Russia, Ukraine, the IUCN Red Data Book.
The Atlantic sturgeon is caught during the course, mainly in the rivers with gill nets. The fish is sold chilled, frozen, salted and smoked. Caviar is used for salting. The quality of caviar and meat of Atlantic sturgeon is lower than that of brackish and freshwater species.
Literature:
1. Lebedev V. D., Spanovskaya V. D., Savvaitova K. A., Sokolov L. I., Tsepkin E. A. Fish of the USSR. Moscow, Mysl, 1969
2. L. S. Berg. Fish of fresh waters of the USSR and neighboring countries. Part 1. Edition 4. Moscow, 1948
3. A. V. Neelov. Fish. L.: Lenizdat, 1987.-- 157 p., Ill. - (The nature of the Leningrad region).
4. P. I. Zhukov. Fish of Belarus. Publishing House "Science and Technology", Minsk, 1965
5. Atlas of freshwater fish of Russia: 2 vols. Vol. 1. / Ed. Yu. S. Reshetnikov. -M.: Nauka, 2003.-- 379 p.: ill.
6. Commercial fish of Russia. In two volumes / ed. O. F. Gritsenko, A. N. Kotlyar and B. N. Kotenyov.- Moscow: VNIRO publishing house. 2006. - 1280 s. (Volume 1 - 656 p.).
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