Fish book son indd

G.M.Palatnikov,  R.U.Qasimov
120
subsequent years, the nereis together with higher crustaceans are the main 
food of the starred sturgeon; however, alongside with nereis and mollusks, 
fi sh - mainly herrings and gobies - play a signifi cant role in the food supply 
of starred sturgeons at feeding grounds of the Middle and Southern Caspian.. 
Of herrings, the starred sturgeon prefers common and anchovy kilkas and 
gobies.
There are early- and late-run starred sturgeon stocks; spawning occurs 
from April to September. Spawning grounds are located on a pebbled bott om. 
Following runoff  control activities, only fi ve channel spawning grounds, with 
an area of 112.8 hectares, survived out of 53 hectares of spawning grounds for 
sturgeons in the Kura River and 290 hectares in the Aras River. In the Volga 
River, the area of spawning grounds has been reduced by a factor of seven, 
which has led to a sharp decrease in the number of sturgeons, including 
starred sturgeon.
The fecundity of females is between 30,000 and 600,000 eggs. Aft er 
spawning, juveniles and spawners migrate to the sea.
Due to the damming of many rivers through a chain of hydroelectric 
power plants, the eggs of starred sturgeons are incubated in hatcheries, and 
the bred juveniles are released into natural water reservoirs.
The minimum age of starred sturgeon males in the commercial sites on 
the Ural and Volga Rivers is 5-6 years. En masse males reach sexual maturity 
at the age of 11-15 years; females – at 14-18. The number of males younger 
than 12 years of age found in catches is approximately 10 times higher that 
of females.  At the age of 12-15, the preponderance of males over females is 
reduced by a factor of two; from the age of 15 – females dominate over males. 
Aft er 25 years, the share of males and females does not exceed 0.3-1.1%. The 
maximum age of males in the population is 27 years; of females – 30-31. The 
starred sturgeon easily cross-breeds with the sterlet and barbel sturgeon.
Starred sturgeon meat has high taste qualities, may be kept in cold and 
frozen forms, and can be used for preparing dried and smoked balyk products. 
The caviar is used for the production of pressed and granular caviar, as it is 
fi ner and less valuable than the caviar of the sturgeon and beluga.
The starred sturgeon swim bladder makes the best isinglass.

---

Sturgeons – contemporaries of dinosaurs
121
STERLET – Acipenser ruthenus Linn’e, 1758
Common names: Russian – sterlyad; Azerbaij an  –  chyakya; English – 
starlet, or sterlet.
In general the sterlet inhabits the rivers of the Caspian Sea, Sea of Azov, 
Black Sea, and Baltic Sea basins. It is a freshwater fi sh that consistently lives 
in the Volga and its tributaries, as well as the Ob and Irtysh rivers.  It also 
is found, although rarely, at the western coast of the Caspian.  The sterlet 
was recorded in the Baku and Kizil-Agach bays, from where occasional 
species enter the Kura River. The sterlet is well-known in the Danube – as far 
upstream as Vienna. There are historical records of the presence of sterlets in 
the Kvaerner Gulf (northern part of the Adriatic Sea). Through a system of 
channels, sterlets entered the Northern Dvina, as well as Lake Ladoga and 
Lake Onega basins. In Siberia, this fi sh is found in the Ob, Irtysh and Yenisei 
Rivers. There are no sterlets in the Pyasin, Khatang, or Lena, nor in rivers 
further to the east, as well as the Amur (the Ob sterlet was transferred to the 
Amur River).
The sterlet is easily distinguished from all other sturgeon species by its 
size and its long narrow snout, long fringed barbels reaching the mouth, bi-
septate lower lip, and contacting side scutes. As already stated, instead of 
the usual scales, all sturgeon species are covered with bony plates (scutes), 
arranged on the body in fi ve lateral rows, of which one occupies the middle 
of the fi sh back, two are located on each side, and two – on the belly along 
its edges; the area of skin between these scutes either is bare or covered with 
minor bone scutes of various forms. Additionally, the sterlet’s dorsal scutes 
are closely spaced; they number between 13 and 17, and each ends behind 
with a rather sharp spine. The sterlet has very many lateral scutes – between 
60 and 70, as well as 13-15 ventral scutes, and the latt er do not contact one 
another.

---

G.M.Palatnikov,  R.U.Qasimov
122
The color of sterlet changes, subject to the location, and may be more or 
less yellow. But the usual color of its back is grayish-brown or dark-brown; 
its belly – yellow-white; its fi ns – gray. The length of the sterlet’s snout is also 
subject to signifi cant changes, and in many areas fi shermen diff erentiate the 
sharp-nosed sterlet and the tube-nosed sterlet.
Most rivers are inhabited by sharp-nosed (typical form, according to Berg) 
and tube-nosed sterlet forms. The sterlets were transferred from the Northern 
Dvina to the Daugava River (Western Dvina), as well as to the Mezen, Neman, 
Onega and Pechora Rivers and to the Shuya (Onega Lake basin). In addition, 
the Ob sterlet and the sterlet-sturgeon hybrid were transferred from the Ob to 
the Amur. The sterlet was transferred to some lakes as well. The tube-nosed 
(early-run) sterlet in the Volga and Kama grows quicker that the sharp-nosed; 
it is more well-nourished and fertile. Usually, a commercial sterlet is 0.5-2 kg 
in weight and 30-65 cm in length; it rarely is 3-4 kg in weight and 80-90 cm 
in length, and a 6-8 kg sterlet is an exception. The maximum weight of the 
sterlet is 16 kg; maximum length – 100-125 cm.
The sterlet prefers to live at the deepest spots in rivers, always staying 
(creeping)at the bott om, and leads a very hidden life. It moves to shallow 
areas (into grass and towards shores) only in the evenings or at nights, and it 
either searches all holes and burrows of the river bans or rises to the surface 
and gingerly, as if on the prowl, turns belly up and catches with its mouth the 
insects falling into the water.
Sterlet males reach sexual maturity at the age of 3-7 (mostly at 4-5) years; 
females – at 5-12 years (mostly at 7-9) aft er reaching a length of 28-34 cm. 
Fecundity of the Ob sterlet is between 6,000 and 45,000 eggs; the Irtysh sterlet 
– between 6,000 and 16,000 eggs; and the Northern Dvina sterlet – between 
4,000 and 140,000 eggs. Sterlets spawn in 1-2 years. Males in the Volga become 
adults at the age of 3 years; females spawn in the sixth year of their life. The 
Volga has both the early- and the late-run types of sterlet. Spawning takes 
place in spring, from late-April to June, at a water temperature of between 
7-10 and 20° C, on a pebbly fl oor with a high water fl ow rate. An egg is gluey, 
1.9-2 mm in diameter. The incubation stage lasts four-fi ve days. The prolarva 
yolk sac is absorbed, depending on the temperature, over 6-10 days.
The sterlet feeds on invertebrates, mainly insect larvae, resting on 
submerged snags. It devours the larvae of chironomids.
In nature the sterlet yields hybrid forms with sturgeon and starred 
sturgeon (sturgeon ship, starred sturgeon ship). The sturgeon ship is rather 

---