Fish book son indd

Sturgeons – contemporaries of dinosaurs
111
The Kura River is the main spawning ground on the Azerbaij an coast. 
Sturgeons used to migrate up the Volga – upstream of Tver city, up the Dnepr 
– upstream of Kiev, and up the Kura – to Tbilisi.
From the Black Sea, sturgeons enter the Danube and Dnepr; very few 
enter the Rioni, Mzymta, Psou, or other rivers.
For spawning, sturgeons from the Sea of Azov enter the Don river and, 
in small numbers, the Kuban river. Recently,, the migration of sturgeon (and 
beluga) to the Kuban River has been increased.
Volga sturgeon males reach sexual maturity no earlier than the age of 10; 
for females – no earlier than 13.
Kura sturgeon males reach sexual maturity at the age of 13-14; for females 
– 19-30.
Sexual maturity for Azov sturgeons: males – 8-9 years; females – 10-14; 
the Dnepr sturgeon matures no earlier than the age of 11.
The maximum recorded age – 48 years; maximum length – 230 cm and 
weight (rarely) – up to 80 kg and even 120 kg.
The average commercial weight of the Volga sturgeon is 12-16 kg. In 
1960, the average weight of the Volga sturgeon was 14.5 kg; in 1962, the 
average weight of migrating male sturgeon in the Volga was 11.7 kg, and that 
of females – 21.3 kg.
The average commercial weight of the Kura sturgeon is 22-24 kg; and 
that of  the Azov sturgeon –approximately 15 kg.
The Russian sturgeon’s fecundity varies from 84,000 to 837,000 eggs; it 
makes  250,000-350,000 eggs in average.
Sturgeon, as well as all sturgeon species, undergoes the following stages 
in its life circle: embrio, prolarva, larva, alevin, juvenile, and adult. Embrio 
undergoes the following fi ve stages: 
fertilization, 
- 
fi ssion, 
- 
gastrulation, 
- 
post-gastrulation till pre-heart beat,
- 
heartbeat – egging from the beginning of the heart beating to the 
- 
emergence from eggs.
The prolarva period begins with the embryo’s release from membranes 
and ends with it transitioning to active exogenic feeding.

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G.M.Palatnikov,  R.U.Qasimov
112
Sturgeon larvae that have all lateral and ventral scutes, rays along the 
dorsal blades of the caudal fi n, a short, rounded snout that makes up less than 
50% of the length of the head, and middle barbels that reach the snout edge, 
are considered as juveniles. A juvenile that reaches maturity is considered to 
be an adult.
In order to grow normally, sturgeon needs a set of favorable conditions of 
the aquatic environment, with certain amplitude in fl uctuation; temperature 
and oxygen regime, reaction of the environment, water fl ow, and the absence 
of contamination and predators. With oxygen defi ciency and reduction 
of oxygen concentrations in the water up to 5-6 mg/l, a delay in embryo 
development is observed. During spawning of sturgeon in the Volga River, 
oxygen concentrations in the water should be no less than 10.1-8.2 mg/l. 
Industrial waste water, oil and other pollutants of the river water may have 
an adverse eff ect on the development of embryos and juveniles of the Russian 
sturgeon, as well as of other sturgeon species. Oil, which sett les on the river 
bed together with particles of suspended solids in the river, is particularly 
dangerous for developing eggs.
In the Caspian Sea, sturgeon at an early age feeds on invertebrates 
(crustaceans, mollusks, annelids, etc.) and, as it becomes mature, it begins to 
feed on mollusks and fi sh (gobies, shads, kilkas).
Sturgeon in nature gives rise to hybrid forms with beluga, starred 
sturgeon, barbel sturgeon, and sterlet species. Through artifi cial fertilization, 
viable hybrids have been achieved:  sturgeon x sterlet, sterlet x sturgeon, 
sturgeon x beluga, and beluga x sturgeon.
Eff ect of anthropogenic factors on the species:
regulated river stream fl ow;
- 
poaching industry;
- 
water contamination.
- 
For a long time (1931-1940; 1951-1962), the commercial fi shing of the 
sturgeon population in the Caspian Sea has been growing intensively. During 
river harvesting between 1962 and 1981, the rate of sturgeon extraction in 
the Volga-Caspian basin remained low. The numbers and biomass of the 
population were underutilized. With a new method of harvesting introduced 
in 1981, the intensity of fi shing sharply increased, and as a result, the amount 
and biomass of the spawning population began to decrease, leading to the 
reduction of the natural reproduction. The high rate of harvesting in the 
Ural-Caspian basin in the 1970s-1980s also contributed to the reduction of the 

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Sturgeons – contemporaries of dinosaurs
113
sturgeon population. Artifi cial breeding in hatcheries, initiated in the mid-
1950s, was a counter measure for the preservation of the species.
Beginning in the 1990s, illegal poaching became the main factor of the 
sturgeon population reduction both in the sea and in the rivers.
RUSSIAN STURGEON has been recorded in the International Red List.
Persian sturgeon Acipenser guldenstadti persius
Borodin, 1897
Related forms: other species of the Acipenser family.
Common names: Russian – persidskiy osetr; Azerbaij an  –neresi; English 
–Persian sturgeon.
The Persian sturgeon lives in Middle and Southern Caspian, preferring 
the warm waters.
Unlike the Russian sturgeon, the Persian sturgeon’s body is more 
elongated, bluish in shade, with a longer head – 17.6% of the total length, and 
a bigger snout and postorbital space. Its snout has a characteristic structure: 
in profi le it is visibly bent downwards and comparatively short and pointed, 
but more bulky than that of the Russian sturgeon. The Persian sturgeon’s 
body thickness and volume is larger than that of the Russian sturgeon. Large 
bony platelets are randomly distributed above the lateral row of scutes. The 
lateral rows have 20-42 scutes with radial grained ribs; the ventral rows have 
7-14 scutes.
The Persian sturgeon can be 2 m long.
It is a valuable commercial species. The highest catches in the Azerbaij ani 
waters of the Caspian were registered in 1936-1940. By the early 1950s, the 
catch decreased to 630 tons, and by the 1950s – to 310 tons. Catches in Iranian 

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