Sturgeon Fish (Acipenseridae)

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Sturgeon Fish (Acipenseridae)
Sturgeon Fish (Acipenseridae)

Video: Sturgeon Fish (Acipenseridae)

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Video: Sturgeon facts: an anadromous fish | Animal Fact Files 2023, February
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Modern sturgeon fish are among the most ancient fish on Earth. They have been known since the Cretaceous. The body is elongated, fusiform. Fish of this family differ from all other fish by the presence of 5 rows of bone beetles: 1 dorsal, 2 lateral and 2 ventral. Small bone plates and grains are scattered between the rows of beetles. The head is covered from above with touching or almost touching bony scutes. The snout is elongated, xiphoid or conically pointed. The mouth on the underside of the head is in the form of a transverse slit or semicircular, on the underside of its 4 antennae, with fleshy lips.

Sharp-nosed sturgeon (Acipenser oxyrhynchus), photo photograph
Sharp-nosed sturgeon (Acipenser oxyrhynchus), photo photograph

Sharp-nosed sturgeon (Acipenser oxyrhynchus)

The jaws (and palatine-square cartilage) are retractable, without teeth in adults; rudimentary teeth are on the palate. There are no branchial membrane rays. Gill rakers are not numerous. Ribs well developed. The tail fin is asymmetrical; the end of the spine curls sharply into the upper, very long lobe of the caudal fin, covered with rhombic scales. The first ray of the pectoral fins is turned into a thorn. There are no vertebrae, the place of the spine is taken by an elastic cartilaginous dorsal string - the chord.

The supraorbital sensory canal runs between both nasal openings on each side. The internal skeleton of sturgeon consists entirely of cartilage. Instead of the spine, it has a typical chord, the cartilaginous membrane of which, when dried, gives a valuable food product - vyzigu. Body length from 50-100 (shovelnose, sterlet) to 900 cm (beluga).

Common shovelnose (Scaphirhynchus platorynchus), photo photograph
Common shovelnose (Scaphirhynchus platorynchus), photo photograph

Common shovelnose (Scaphirhynchus platorynchus)

In prelarvae, the body is elongated, the tail is shorter than the body. The yolk sac is very large, ovoid. The head is bent to the yolk, the eyes are small, the diameter of the eye does not exceed 1/4 of the height of the head. The eyes are poorly pigmented. The snout is blunt and short. Lower mouth.

The body of the larvae is elongated. The tail is shorter than the body. The head is large, the snout is elongated. Lower mouth, 4 antennae in front of it. Caudal fin large, heterocercal. There is a lot of pigment on the body of the larvae. Larvae over 60 mm in length already have all the features of adult fish.

The sturgeon family includes freshwater, semi-anadromous, anadromous fish that inhabit the waters of the northern hemisphere - Europe, Asia and North America. There are 2 kinds in the Black Sea. The sturgeon family has 4 genera with 24 species; within the CIS there are 3 genera with 14 species, in the Russian Federation - 11 species. A number of sturgeon species were included in the Red Data Book of the USSR, and then in the Red Data Books of individual CIS countries.

Sterlet (Acipenser ruthenus), photo photography
Sterlet (Acipenser ruthenus), photo photography

Sterlet (Acipenser ruthenus)

Sturgeon are the most valuable of the commercial fish. The caviar of sturgeon (beluga and stellate sturgeon) is especially highly valued.

In the last quarter of a century, a new species of sturgeon, bester, has appeared in the Sea of ​​Azov. It is a hybrid of beluga with sterlet (female beluga and male sterlet). It was bred artificially in 1952. scientist N.I. Nikolyukin. Outwardly, the bester looks like a beluzhon and at the same time is easily distinguished by the fact that its gill membranes are accreted to the intergill space and the first dorsal bug is noticeably larger than the next two.

Sturgeons easily give crossbreeds among themselves, which on the Volga and on the Caspian Sea are called thorn, kerim, and visas on the Black Sea. Known (in nature) crossbreeds of beluga and sturgeon, beluga and stellate sturgeon, beluga and sturgeon, kaluga and Amur sturgeon, thorn and stellate sturgeon, sterlet and sturgeon, sterlet and stellate sturgeon, Russian sturgeon and stellate sturgeon, Siberian sturgeon and sterlet.

Sevruga (Acipenser stellatus), photo photograph
Sevruga (Acipenser stellatus), photo photograph

Sevruga (Acipenser stellatus)

Anadromous sturgeons have seasonal forms: spring, which enters rivers from the sea in spring and spawns in the spring and summer of the same year, and winter, which rises into rivers usually in autumn (and in other cases even earlier) and spawns the next year after spending winter in the river.

The largest 2 species of the genus Huso: beluga N. huso lives in the Black, Azov, Caspian Seas and in the eastern Mediterranean; for reproduction goes to the rivers flowing into these seas; Kaluga N. dauricus inhabits the basin of the r. Amur and does not go out to sea further than the Amur estuary. Sexual maturity occurs at the age of 9-23 years, with a length of 1.5-2 m.Some individuals live up to 100 years, reaching 5.5 m in length and weighing more than 1.5 tons. Female spawns 0.5-5 million eggs with a diameter 3-4 mm. They do not breed every year.

Systematics of the Sturgeon family:

  • Subfamily: Acipenserinae =

    • Genus: Acipenser Linnaeus, 1857 = Sturgeon

      • Species: Acipenser baerii Brandt, 1869 = Siberian sturgeon

        • Subspecies: Acipenser baeri baicalensis A. Nikolski, 1896 = Baikal sturgeon
        • Subspecies: Acipenser baerii baerii Brandt, 1869 = Ob sturgeon
        • Subspecies: Acipenser baerii stenorhynchus A. Nikolsky, 1896 = Long-snout Siberian sturgeon, or khatys
      • Species: Acipenser brevirostrum Lesueur, 1818 = Blunt sturgeon
      • Species: Acipenser fulvescens Rafinesque, 1817 = Lake sturgeon
      • Species: Acipenser gueldenstaedtii Brandt, 1833 = Russian sturgeon, or Caspian-Black Sea
      • Species: Acipenser medirostris Ayres, 1854 = Pacific, or green sturgeon
      • Species: Acipenser naccarii Bonaparte, 1836 = Adriatic sturgeon
      • Species: Acipenser nudiventris Lovetsky, 1828 = Thorn

        Subspecies: Acipenser nudiventris derjavini Borzenko, 1950 = Kura thorn

      • Species: Acipenser oxyrinchus Mitchell, 1815 = Long-snout sturgeon
      • Species: Acipenser persicus Borodin, 1897 = Persian sturgeon
      • Species: Acipenser ruthenus Linnaeus, 1758 = Sterlet

        Subspecies: Acipenser ruthenus marsiglii Brandt, 1833 = Siberian sterlet

      • Species: Acipenser schrenckii Brandt, 1869 = Amur sturgeon
      • Species: Acipenser stellatus Pallas, 1771 = Sevruga
      • Species: Acipenser sturio Linnaeus, 1758 = Atlantic sturgeon
    • Genus: Huso Brandt, 1869 = Beluga

      • Species: Huso dauricus Georgi, 1775 = Kaluga
      • Species: Huso huso Linnaeus, 1758 = Beluga
  • Subfamily: Priscosturioninae =
  • Subfamily: Propenserinae =
  • Subfamily: Psammorhynchinae =
  • Subfamily: Scaphirhynchinae =

    • Genus: Pseudoscaphirhynchus A. Nikolski, 1900 = False shovelnose

      • Species: Pseudoscaphirhynchus fedtschenkoi Kessler, 1872 = Pseudo-spatula syrdarya
      • Species: Pseudoscaphirhynchus hermanni Kessler, 1877 = Amudarya small pseudo-spatula
      • Species: Pseudoscaphirhynchus kaufmanni Bogdanov, 1874 = Amudarya large pseudopatonos
    • Genus: Scaphirhynchus Heckel, 1835 = Shovelnose

      Species: Scaphirhynchus albus Forbes et Richardson = White Shovelnose

Literature:

1. N. Svetovidov. Fish of the Black Sea. Moscow-Leningrad, 1965

2. A short guide to vertebrates. I.M.Oliger. M., 1955

3.N.P. Naumov, N.N. Kartashev. Zoology of vertebrates. Inferior chordates, jawless, fish, amphibians. Moscow "Higher School", 1979

4. L. S. Berg. Fish of fresh waters of the USSR and neighboring countries. Part 1. Edition 4. Moscow, 1948

5. P. I. Zhukov. Fish of Belarus. Publishing House "Science and Technology", Minsk, 1965

6. AF Koblitskaya. Key to juvenile fish of the Volga delta. Publishing house "Science", Moscow, 1966

7. Yanovskiy E.G. Fish of the Azov Sea. Berdyansk - Lviv: Vidavnytstvo "Good Heart", 2001. - 92 p.

8. 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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