(1758) Huso huso linne
The Beluga Sturgeon is the largest species of fish in the Caspian Sea with a maximum catch weight of 1500 to 2000 kg and maximum caviar up to 117 kg. Due to the very high value of caviar, the stock of this species in the Caspian Sea has unfortunately declined sharply, The production of beluga sturgeon, which decreased from about 43 tonnes in the years 50-51 to less than 1 ton. The minimum body length of Beluga caught in the Iranian coast is 128 cm and in the case of females 202 and 186 cm. The average body weight of female fish was about 98 kg and for male fish was 76 kg.
Most fish caught were between the ages of 10 and 17 years, with a minimum caviar of 2.7 kg per fish and a maximum of 71 kg. And the average caviar extracted per female fish during these years has been reported at about 15 kg. The average number of oocytes per gram when female elephants are about 30 to 35 and the largest size of caviar or oocyte among Caspian sturgeon is about 4 mm in diameter.
Suitable for artificial reproduction operations. The bony bumps are 9 to 17 in the dorsal row and 7 to 14 in the abdominal surface. Distribution of this fish is in the Caspian Sea, Azov and the Black Sea and is scattered throughout the Caspian Sea and in the southern Caspian Sea most of its stocks are located in its eastern basin. The pubertal age of this fish is higher than other sturgeon species in natural conditions, with the male Beluga at 12 to 14 years of age and the female beluga at 14 to 18 years. The beluga has two spring and autumn migratory races and migrates to the rivers Volga, Cora, Ural and the White River to the southern part of the Caspian Sea.
1897 Acipenser persicus Borodine
Acipenser persicus Borodine is one of the most important species of sturgeon in the southern part of the Caspian Sea and has two spring and autumn migratory breeds. The average body length of sturgeon was 159 cm for males and 154 cm for females and average weight was 29 kg for females and 14 kg for males and average age was 14 to 16 years. The minimum extracted caviar is one kilogram of caviar and its maximum is 13.7 kg and the average caviar is about 5.5 kg. The average number of breeding eggs is 50-45 for breeding. Dorsal bony plaques are 7 to 19, lateral dorsiflexes 23 to 50 and abdominal two rows 7 to 13.
The body color in the back is dark and between the dorsal and lateral bumps there are beautiful and stellar motifs. The head of this fish has a slight incline toward the snout and in the middle of the bowl the head is round and black and the mouth is oval and the upper lip has a cut in the middle and has two pairs of shoulders under the head that are mouth to mouth. And its no snout.
The major distribution of these fish is in the southern part of the Caspian Sea and has two spring and autumn migrations. Fish that enter the river in late fall and winter will hatch next spring and generally sooner than migratory spring fish. The natural spawning of these fish occurs in the rivers Sefidrood, Tajan, Gorgan River and Kura River. Although in the present situation there seems to be no natural spawning in these rivers, although according to the data of the Iranian Fisheries Company, the total catch of the sturgeon has decreased, but fortunately with the establishment of sturgeon breeding and breeding centers, Increase in release of sturgeon (especially the species of sturgeon) has increased from 2.4% in 1351 to 69% in 1373.
1833 Acipenser quldenstadti Brandt
Acipenser gueldenstaedtii is the most important species of sturgeon in the northern Caspian Sea and has two spring and autumn breeds and there are considerable stocks of Acipenser gueldenstaedtii in the southern Caspian Sea, but in recent years its release rate has been minimal and as a result of fishing. It increased from 6.89% of total sturgeon catches in 1351 to 27% in 1374. The mean body lengths for males and females were 125 and 134 cm, respectively, and the average body weight of males was 17 kg.
The minimum extracted caviar is one kilogram of fish and the maximum is 11.1 kg and the mean caviar is 4.7 kg. The average number of eggs per gram is about 50.
The number of bony protrusions on the back of the body is 18-8, on the flanks 50-24, and on the abdominal surface there are 13-16. On the skin of the body, there are stellar motifs between the dorsal and lateral protrusions. To different populations, the color of the skin on the underside of the body is yellowish. The head position in the Chalbash fish has a steeper slope to the snout than the Gharbun fish and also has a shorter and circular snout. The crescent mouth and lower lip have a relatively deep cut in the middle and have two pairs of mustaches that do not reach the fish mouth. These fish live in the Caspian Sea, Black Sea and Azov. Migration for oviposition occurs mainly in the spring and autumn, along the rivers Volga, Ural, Kura, Turk, Solak, and the southern part of the Caspian Sea to the Sefidrud and Gorganrood rivers.
(1828) Acipenser nudiventris lovetski
This species is one of the rare and rare fishes in the Caspian Sea, Which hunting them decreases each year, so it is on the red list of the protected species of the EPA. The amount of sturgeon caviar extracted was 4% of the total caviar extracted in the southern Caspian Sea. As the name implies, this fish has a bare belly and its bony features have disappeared.
The average body length of this fish was 152 for females and 135 cm for males and the average weight for females 30 and males was about 20 kg and the average age of fish caught was about 13 to 15 years. The minimum caviar extracted from the fish was 0.3 kg and its maximum was 6.1 kg and the mean caviar was about 5.4 kg.
The number of oocytes in one gram is about 60 to 65 in suitable breeding stock. The number of dorsal rows is 11 to 17, the lateral rows are 49 to 74 and the two rows of abdominal protrusions are almost extinct and 11 to 17. It is noteworthy that the first bony prominence in the dorsal ridge of this – decomposed and 11 fish larger than other Caspian sturgeons is a mild slope towards its sharp snout and the mouth of the crescent shaped but lips united and cut. It has two pairs of stringed mustaches.
The limited distribution of this fish is present in the southern Caspian Basin and has been present in the Black Sea and Aral lakes for years, but is now considered an endangered fish.
The migration of this fish for spawning occurred simultaneously with other sturgeons in the Sefid Rud, Kura, Ural and formerly in a very limited number on the Volga River. Baby fish do not migrate to the sea in natural and suitable conditions, but some remain in the river for more than a year and then migrate to the sea.
(1771) Acipenser stellatus pallas:
The fish in the Caspian Sea consists of two species north and south of the Caspian Sea with different populations and is also called Dracula and Soroga. Artificial reproduction of ozone in recent years has always been problematic due to physiological problems and lack of proper sexual maturity of the breeders. The average length of the fish in the southern Caspian Sea was 111 cm for males and 120 cm for females and the mean weight for males was 7.6 and females 11.4 kg. The mean age of caught fish was between 10 and 12 years.
The minimum caviar extracted from ozone was 1.3 kg and its maximum was 6.1 kg and the mean caviar obtained from female was 2.4 kg. And the number of eggs per gram in female broods is 70 to 75.
One of the most important signs in the diagnosis of this fish is its long snout, which accounts for about 60 percent of its head length. The mouth of this fish is almost rounded in the middle and has a cut in the middle and also two pairs of short, unbranched mustaches that do not reach the mouth. The number of bone bumps in the dorsal row is 16 to 19 in the flanks 26 to 43 and in the abdominal surface 9 to 14 in the dorsal and lateral bumps, respectively.