Fish book son indd

G.M.Palatnikov,  R.U.Qasimov
144
basin: Chardarya, Farkhad and Kayrakkum. The sturgeons spawned during 
the second half of April, on the stream over rocky bott oms. They att ained 
sexual maturity at the age of 6. The fertility rate is 850 to 1,500 eggs. The roe 
is small, 1.3-1.8 mm in diameter.
This sturgeon feeds mainly on small bott om-dwelling invertebrates. It 
has always been a rare species. The reasons for their decreasing numbers are 
the same as for false shovelnose sturgeons - regulation of the Syr Darya River 
fl ow, water off -take for irrigation purposes and violation of the conditions in 
which they reproduce. There have been no reported catches of the Syr-darya 
shovelnose sturgeon for the last twenty or thirty years. It could still remain in 
the upper unregulated part of the Syr Darya, which is still poorly studied. A 
fi sh survey needs to be performed in this area as soon as possible and if the 
shovelnose sturgeon has been preserved there this area must be put under 
special protection and declared a natural reserve.

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Sturgeons – contemporaries of dinosaurs
145
PADDLEFISH FAMILY (POLYODONTIDAE)
In contrast with sturgeon, paddlefi shes do not have any scutes. They have 
an elongated and slender body, which is either ‘naked’ or covered with small 
scatt ered plates, and a very long snout in the shape of an oar or sword, with 
two small barbels on its lower surface. The side line grooves on the head and 
body are surrounded with bonelets. The young individuals have small teeth 
on their jaws. In respect of their other features they resemble sturgeon.
There are only two extant species of these fi sh: the American and the 
Chinese paddlefi sh.
The American paddlefi sh (Polyodon spathula) lives in the waters of lakes 
and rivers of the Eastern part of the USA down to Texas and in the Mississippi 
River system.
American paddlefi sh (bottom and side view)
The American paddlefi sh (Polyodon spathula) is quite a large freshwater 
fi sh that reaches over 2m in length and can weigh over 70 kg; in the early 
1960s the average fi sh weight in catches was 14 to 16 kg. They occur in 
the Mississippi River and its tributaries, the Ohio, Missouri and Illinois and 
in other rivers fl owing to the Gulf of Mexico, as well as in a number of lakes 
connected to the Mississippi River system.
The distinguishing feature of the appearance of the American paddlefi sh 
is its long snout (rostrum) that has the shape of an oar and makes up to 1/3 of 
the entire body length. Its mouth is non-protractile.

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G.M.Palatnikov,  R.U.Qasimov
146
The American paddlefi sh is the only species of sturgeon that feeds on 
zooplankton. It swims in the water column with its mouth open wide and fi lters 
pelagic crustaceans using its gill rakers which are long and closely spaced; here 
its fl at snout plays the role of a trail cover. It is aptly called a living plankton 
sampler. Insect larvae are found much more rarely in the guts of the fi sh.
The American paddlefi sh spawn in the Mississippi between late April 
and early May at water temperature of 14-16 deg C. The eggs are laid on the 
gravel bott om at a depth of 4.5-6 m and hatch over 9 days at a temperature 
of 14 deg C. The fertility rate is between 82,000 and 269,000 eggs. In terms 
of their structure, color and how they develop the eggs are very similar to 
those of a sturgeon. Their diameter is approximately 2.5 mm. The American 
paddlefi sh gather in big shoals when they are going to spawn. This species 
does not spawn every year. The minimum length (age) of sexually mature 
males and females is 100cm (7 years) and 130 cm (13-14 years), respectively. 
In the early 1940s the annual haul of these fi sh in the USA amounted to about 
10,000 hwt. Their roe was of special value. Later on anthropogenic factors 
resulted in this species diminishing, and some att empts were made to rear it 
artifi cially. The American paddlefi sh is also of interest in terms of its possible 
introduction in our southern water bodies and use in aquaculture.
The Chinese paddlefi sh (Psephurus gladius) lives in the Yangtze River, China.
The Chinese paddlefi sh (
Psephurus gladius
)
Its biology is poorly studied. The largest freshwater fi sh in the world, 
the Chinese paddlefi sh reaches 7 m in length. It has a sword-shape rostrum 
that makes up to 1/3 of its entire body length. In contrast with the American 
paddlefi sh, the Chinese paddlefi sh has a protractile mouth and diff ers from 
the former not only in its size but in its tastes: it is not content to feed on 
plankton, but also hunts large fi sh. 
This species is so rare that its habits are virtually unknown. Due to its 
rarity it is of insignifi cant commercial importance.

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Sturgeons – contemporaries of dinosaurs
147
WHAT DOES MAN
GET FROM STURGEON?
Fish has been one of the main sources of protein for man since long time. 
Its exceptional edibility and tastiness, and easy availability made the sturgeon 
a subject of hunting long before the beginning of our era. No any other fi sh 
family has ever been exploited by man for so long and so intensively! Today 
sturgeon is still a very valuable commercial commodity. Its caviar and meat 
are highly valued on the world market. For this reason commercial hauling 
of these fi sh has always been highly intensive.
In the Middle Ages large shoals of sturgeons moved up many European 
rivers including the Thames in England, the Seine and Gironde in France, the 
Po in Italy, the Ebro and Guadalquivir in Spain, as well as the upper reaches of 
the Danube. There were so many sturgeons in Germany that labor contracts 
even included a clause which prohibited making workers eat fi sh more than 
twice a week.
In Russia sturgeon was a source of food as early as the XII century, while 
the Europeans were afraid to consume it for another fi ve centuries.
Don’t believe it when people try to tell you that in Russia black caviar 
has long been a luxury delicacy. This is not exactly true. The traveler William 
Cox wrote that during the reign of Catherine II in the Summer Garden in St 
Petersburg on one of the feast-days the tables for common people ‘were strewn 
with all kinds of delicacies: high pyramids of bread hunches with caviar, dried 
sturgeon, carp and other fi sh decorated with crayfi sh, onions and cucumbers.’ 
The princes and boyars did not consider caviar a delicacy, preferring to have 
golden pike caviar on their tables. However, the common people did not 
shrink from eating sturgeon caviar. A universal food item was pressed and 
especially saccate caviar, which was purchased by poor people. Late XVIII 
century Prince Peter Bagration enlisted Marie-Antoine Careme, a recognized 
authority in European cookery, who had once worked in Cuba and had been 
a personal chef to the banker Rothschild, and even the British king. In his 
lett ers home the all-time king of all French chefs described in great detail the 
particular features of the Russian way of life and, of course, the cuisine. The 

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