brine shrimp artemia
(crustacea, branchiopoda, anostraca) in uzbekistan
I.M. Mirabdullayev, N.I. Jumaniyazova, S.
Kazakhbayev, A.R. Kuzmetov, D.S. Niyazov, I.M. Joldasova-2002
TETHYS Aqua Zoological Research, Volume I
Crustaceans of the genus Artemia are members of the
order Anostraca, one of the evolutionary most primitive in the subphylum
Crustacea. Brine shrimps are widely distributed in hypersaline waterbodies
of almost all continents. In Central Asia Artemia was recorded in western
Turkmenistan (Lake Karabogaz Gol), in lakes of northern Kazakhstan, in some
mountain lakes in Pamir (Tajikistan). There are practically no data on the
presence of Artemia in Uzbekistan. So, Artemia is not mentioned in the basic
monography on Crustacea of the Ferghana Valley (Mukhamediev, 1986). The only
record of Artemia (“Artemia salina”) in Uzbekistan is concerned to lakes
in Khorezm Prov. (Khakberdyev et al., 1978).
However, the data collected shows that Artemia is
much more widely distributed in Uzbekistan. During surveys in 1989-2000,
Artemia was recorded in the following waterbodies.
1. Lake Kalajik in the Khorezm Prov., 4 ha,
mineralization 60-80 g/l.
2. Lake Tengeli in the Khorezm Prov., 0.5 ha,
mineralization g/l
3. Ditch in the Khorezm Fishery Farm, Khorezm Prov.
4. Small lake (ca. 0.3 ha) near village Navruz, Jizak
prov.
5. Temporary pool near town Karshi, Kashkadarya Prov.
6. Temporary pool in Bukhara Prov.
7. Small lake on west edge of the plateau Ustyurt,
near Cape Aktumsuk.
8. Small lake near town Muynak, Karakalpak Autonomous
Republic.
9. Temporary pools around the Lake Sudochje,
Karakalpak Autonomous Republic.
10. Temporary pools on the Island Vozroshdeniya in
the Aral Sea; mineralization 20-140 g/l/
11. Aral Sea near east shore of the Aral Sea
(Joldasova et al., 1999).
There are some data on the presence of Artemia in
small saline lakes around the Aydar-Arnasay Lakes in Jizzak Prov., and the
Aral Sea.
Brine shrimps are typical halostenobionts inhabiting
only haline and hyperhaline waterbodies. The optimum of mineralization of
water for Artemia is between 50-200 g/l. With growing salinity of soils and
the number of salt waterbodies in Uzbekistan it is possible to expect
finding of Artemia not only in waterbodies of Khoresm, Jizzak, Kashkadarya,
Bukhara Provinces, and Karakalpak Autonomous Republic, but also in Navoi and
Syrdarya Provinces. The presence of Artemia in Tashkent, Samarkand and
Surkhandarya province is less probable. There is no Artemia probably in the
Ferghana Valley (Mukhamediev, 1986).
Usually Artemia populations reach a significant
density only in waterbodies where competitors and predators are absent
because its only “weapon” in the struggle for existence is Artemia’s
exclusive haloresistance (Van Stappen, Sorgeloos, 1993). In spite of this in
some instances we recorded co-existing of Artemia with other aquatic
invertebrates. For example, in a temporary pool in Kashkadarya Prov. Artemia
co-existed with rotifers Brachionus plicatilis and Hexarthra oxyuris. In
Bukhara Prov., Artemia was recorded to co-exist with Arctodiaptomus salinus,
Thermocyclops vermifer, Diaphanosoma mongolianum; in Usturt it co-exists
with Moina salina, A. salinus, ostracods. In plankton of the Aral Sea,
Artemia co-existed with cladoceran Moina salina, harpacticoids, ostracods,
larvae of Nereis, bivalve mollusks and chironomids. The mineralization of
this part of the sea reached 58.3 g/l (October, 1998) (Joldasova et al.,
1999).
The taxonomic state of Artemia from waterbodies of
Uzbekistan needs clarifying. Traditionally, brine shrimps from Eurasia were
considered as Artemia salina (Leach, 1819). However, recently the taxonomy
of the genus Artemia is considered more complex. By modern views, Artemia
salina (Leach, 1819) is a sexual European species, whereas sexual Artemia
sinica (Cai, 1989), A. urmiana (Günter) and parthenogenetic A.
parthenogenetica are characteristic for Asia (Triantaphyllidis et al.,
1998). The last rather artificial taxon unites populations of brine shrimp
of different ploidy reproducing only parthenogenetically. Phylogenetically,
Artemia parthenogenetica probably are most related to A. urmiana. Amost all
populations recorded by us in Uzbekistan are parthenogenetic and have been
considered as Artemia parthenogenetica. The only sexual population was
recorded in a small lake on Ustyurt. For a more precise taxonomic
determination of this population detailed morphological and biochemical
studies are necessary as well as a breeding experiment.
Interest towards Artemia in Uzbekistan is conditioned
by that it is a commercially important species of aquatic organisms. The
eggs of Artemia are used as the initial food while breeding shrimps and
valuable fish species, and have virtually unlimited export qualities. The
annual collection of Artemia eggs in the world exceeds 7000 tons (1 g
contains over 200,000 eggs). Besides, over 10,000 tons of the Artemia
biomass are used as food for fishes and shrimps (Lavens, Sorgeloos, 1998).
The highest yields of Artemia are obtained in Great Salt Lake in the USA,
the area of which is 4650 km², which, if we take into consideration annual
climatic fluctuations, in the most adverse way affects the world market of
Artemia eggs. In this connection, significant measures have been taken to
open and exploit alternative Artemia sources.
(Institute of Zoology,Tashkent, Uzbekistan)