Fish book son indd

Sturgeons – contemporaries of dinosaurs
157
CAVIAR PRODUCTION. The anatomic structure of the genital system of 
sturgeon females does not allow the ripened roe to be strained off  as it is with 
carp or trout. Therefore, to extract the roe the fi sh belly is cut open and the 
roe is extracted. During this process the fi sh is put on a special bench where it 
is secured. Previously, aft er this operation the fi sh was sent to the fi sh-factory 
for processing.
Today, using the method developed by S. B. Podushkina the roe is 
extracted at the initial stage by straining, and then a cut is made in the rear 
section of the egg tube. Following this the roe can easily be strained off  in the 
normal way.
The incision in the egg tube does not cause bleeding as it is a thin 
translucent membrane. The wound is quite insignifi cant and heals quickly. 
The survival rate of fi sh aft er this operation is close to 100%.
The sperm for roe impregnation is taken from three males and strained 
into a bowl with a catheter.
The sperm is diluted with water and mixed with roe at a rate of 10ml of 
sperm per 1 kg of roe.
ROE HATCHING. Special incubators with a capacity of up to 3 million 
eggs have been developed and put into operation to equip the fi sh hatcheries. 
Weis or Zamanov devices are used for the incubation of a smaller number of 
eggs. The optimum water temperature for incubation is selected depending 
on the sturgeon species, in a range of 13 to 18 deg C.
Starting from the second day of incubation, once every two days the eggs 
are subjected to preventive treatment using the Ch. Mamedov method in 
order to prevent saprolegniosis.
The hatched fries are placed in previously arranged trays.
DEVELOPMENT OF FRY. Sturgeon embryos have a big yolk sac, 
disproportionately large head and poorly developed internal organs. The 
eyes are only discernible as pigment spots. The movement of sturgeon fry 
resembles that of a tadpole. The fries react to light, move in the water column 
and oft en go down to the bott om to form large concentrations, or schools. 
For approximately 7 days the fries develop by consuming the energy they 
receive from the yolk sac and then gradually move on to external nutrition. At 
this stage the fries feed on small aquatic life forms. In the absence of live food 
the fries go down to the bott om and feed on bott om sediments by extracting 
micro-organisms and organic particles from them. 

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G.M.Palatnikov,  R.U.Qasimov
158
The sturgeon fries are held in relatively long (up to 4 m) and narrow 
(between 0.5 and 0.8 m) trays with shallow water (up to 15-20 cm) and 
insignifi cant current. Round or square basins are also suitable for raising fries.
The fries are not very good swimmers and the current can press them 
against the nets at the water outlet. The fries have a surprising ability to 
escape the trays through the tiniest holes. Therefore fry-catching devices are 
installed at the basin water outlet.
When they reach 2.5 cm the fries expand their diet with bott om sediments. 
They dive, dig heaps with their noses and extract the food.
Sturgeons that have reached a length of 3.5-4 cm become strong and can 
withstand external exposure. They can be put into individual basins and fed 
with fi nished pelleted feed. Sterlets, Siberian sturgeons, belugas, besters and 
paddlefi shes progress to pelleted feed quite easily. Other species have a hard 
time moving to artifi cial feed.
RAISING COMMERCIAL FISH. The raised young are either released 
directly into the river from which the spawners were taken or delivered to the 
estuary, to an area for further fatt ening. This technology made it possible to 
hold back the extinction of many commercial sturgeon species in the USSR by 
many years. At present there are 4 sturgeon plants operating in Azerbaij an.
Furthermore, a whole series of laws was drawn up to preserve sturgeon 
populations:
First of all, hauling of these fi shes at sea was prohibited. It was permitt ed 
to haul the fi shes only in rivers and during a strictly limited period of time.
The northern shallow-water area of the Caspian Sea, which is the 
fatt ening ground for adult sturgeons and the place where the young are 
raised, was declared a preservation area and all off shore operations within 
it were prohibited.
All explosive activity in the Caspian Sea, either industrial or military, has 
been banned.
However, the 1950s saw the appearance of a new threat to all life forms 
in the Caspian Sea, environmental pollution. Shortly aft er the end of the 
Great Patriotic War, large plants and factories were built on the Volga and 
in the towns on the shores of the Caspian Sea, with a corresponding growth 
in the population of these towns, with no thought given to treatment plants 
for industrial and household effl
  uents. At the same time off shore exploration 
and production of oil and gas began. The Caspian Sea, a closed water body, 
became a huge trap for toxic substances. No less than 25 percent of all 

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Sturgeons – contemporaries of dinosaurs
159
wastewaters from the entire FSU is discharged into the Volga-Caspian basin. 
Each year the waters of the Kura and other small rivers carry to the sea: 
around 5.24 thousand tonnes of chemical compounds, 2.36 thousand tonnes 
of suspended solids, 1.5 thousand tonnes of petroleum products, 150 tonnes 
of metal compounds and 110 tonnes of phenols; of these, the Kura accounts 
for over 96%. Moreover, the river pollution is 2 to 9 times the sanitary standard 
(sometimes this rate raises to 13.)
The consequences of the negative impact of petroleum products on 
thalassophili are clearly evident from the experience of many years of well 
operation off  the coast of Azerbaij an. A sad consequence of the off shore oil 
exploration and production has been the complete loss of the value of the 
sections between the Cape of Bandovan and the Absheron Peninsula in terms 
of commercial fi shing. Previously this area served as the fatt ening ground for 
young individuals of the Caspian salmon and small Kura fi shes and a fi shing 
ground for kutum and shad. Oil pollution has resulted in the disappearance 
of the pike perch and crawfi shes that used to inhabit the areas around Chilov 
and Oil Rocks, and 25-30 thousand hwt of which used to be hauled per 
annum before off shore oil production started. Such valuable species as barbel 
sturgeon, beluga etc. are critically endangered.
As early as the 1980s Academician Hasan Aliyev proved that refraining 
from off shore oil and gas production in the Caspian, together with the 
development of sturgeon-breeding would provide greater and more stable 
profi t for the government. Unfortunately, these appeals were not heard.
At present the average petroleum hydrocarbon concentration in the water 
of the Caspian Sea is 1.5-2 times the fi shing industry’s maximum permissible 
concentration (MPC); in areas of intensive oil production this indicator is 
dozens and even hundreds of times the MPC. The waters in vicinity of Oil 
Rocks have long been a dead zone.
The average hydrocarbon concentration in the South and Middle Caspian 
is 7-10 times the MPC, while in oil and gas production areas it is 30-100 times 
the MPC. Huge migrating oil spots are encountered in the Middle and South 
Caspian, where it is not possible to haul fi sh, the kilka in particular. Today 
the kilka are being lost on such a huge scale that it is possible to say that its 
commercial hauling has stopped.
Another unique inhabitant of the Caspian Sea, the Caspian seal (Pusa 
caspica), which is the only marine mammal in the Caspian, has also become 
a critically endangered species. They came to the Caspian Sea in time 

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