51813_Sturgeon biodioversity an.PDF

Figure 2.Siberian sturgeon catches in the 1980–1990s in the Ob. Yenisey, and Lena rivers. Data from Kirillov (1972). Yegorov (1988),
Gundrizer et al. (1983), Votinov et al. (1975), Dryagin (1949) and own.

norrhynchus) and Lena (A. baerii chatys) rivers
showed that differences between the fish from
these populations do not reach a subspecific level
(Ruban & Panaiotidi 1994). Comparison of our re-
sults with previous data obtained by the other au-
thors (Menshikov 1947, Dryagin 1948b, Podlesnyi
1955, Sokolov & Vasilev 1989, Ruban 1989, 1992)
points to clinal variation in a number of meristic
characters of Siberian sturgeon(Ruban& Panaioti-
di 1994). Usually it is considered that when the ge-
ographic variation within a species is clinal, it is not
appropriate to name such forms as a subspecies
(Mayr 1969, Holcík & Jedlieka 1994). Therefore, it is
not right to considerA. baerii chatysas a subspecies

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of the Siberian sturgeon and this form should be in-
cluded in the subspecicsA. baerii stenorrhynchus
described by Menshikov (1947) for the fish from
populations of the Yenisey, Lena, and Kolyma riv-
ers (Ruban & Panaiotidi 1994). Additionally, be-
cause of the absence of sturgeon specimens from
the Ob River basin in museum collections, the
problem ofA. b. stenorrhynchus also cannot be
solved definitively. At present one can consider the
Siberian sturgeon to consist of three subspecies: the

nominalA. baerii baeriiBrandt. 1869 from the Ob

River basin, A. baerii baicalensis Nikolsky, 1896

from the Lake Baikal basin, and A. baerii stenor-

rhynchusNikolsky, 1896 from other Siberian wa-

ters.

Contemporary status of A. baerii

As described above, the range of the Siberian stur-

geon is constantly being reduced; the number of in-

dividuals in each population is also decreasing. De-

pletion is caused by three main factors: the elimina-

tion of spawning grounds after the construction of

dam, overfishing, and water pollution.

Fishing

Although the catch of Siberian sturgeon has always

been relatively small and never exceeded 1769 met-

rie tons per year, its impact on the status of different

populations was devastating. The highest catches

were recorded in the Ob-Irtysh and Yenisey rivers