Siberian sturgeon
Encyclopedia
The Siberian sturgeon is a species of sturgeon
in the Acipenseridae family. It is most present in all of the major Siberia
n river basins that drain northward into the Kara
, Laptev
and East Siberian sea
s, including the Ob
, Yenisei
(which drains Lake Baikal
via the Angara River
) the Lena
and Kolyma river
s. It is also found in Kazakhstan
and China
in the Irtysh River, a major tributary of the Ob.
However, recent studies suggest that Siberian sturgeon may be monotypic
, forming continuous genetically connected populations throughout their vast range.
The nominate taxon
(A. baerii baerii) accounts for 80% of all Siberian sturgeon and resides in the Ob river and its tributaries. This subspecies migrates to mouth of the Ob river during the winter due to seasonal oxygen deficiency in the Ob River, and swim thousands of kilometers upstream to spawn
.
The subspecies A. baerii baicalensis known as the Baikal sturgeon
is a unique lake form found primarily in the northern end of Lake Baikal
and migrates up the Selenga River to spawn.
A third form, "A. baerii stenorrhynchus", resides in the eastern Siberian rivers and displays two life history patterns: a more abundant migratory one which swims considerable distances (sometimes thousands of kilometers) upstream from estuaries and deltas to spawn, and a non-migratory form. This form is now considered to be a junior synonym of A. b. baerii.
river channels on stone or gravel substrates.
The Siberian sturgeon feeds on a variety of benthic organisms such as crustaceans and chironomid larvae.
The species had been in steep decline in its natural range due to habitat loss, degradation and poaching
. Up to 40% of the Siberian sturgeon spawning habitat has been made inaccessible by damming. High levels of pollution
in certain places has led to significant negative impacts on the reproductive development of gonads.
both for meat and to produce caviar
from its roe
. Because the Lena population of A. baerii completes its life cycle in freshwater and sexually matures relatively early, it is the most commonly original broodstock
for captive bred specimens. The main producer of Siberian sturgeon caviar is France
, while the largest meat producers are Russia and China.
Sturgeon
Sturgeon is the common name used for some 26 species of fish in the family Acipenseridae, including the genera Acipenser, Huso, Scaphirhynchus and Pseudoscaphirhynchus. The term includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common...
in the Acipenseridae family. It is most present in all of the major Siberia
Siberia
Siberia is an extensive region constituting almost all of Northern Asia. Comprising the central and eastern portion of the Russian Federation, it was part of the Soviet Union from its beginning, as its predecessor states, the Tsardom of Russia and the Russian Empire, conquered it during the 16th...
n river basins that drain northward into the Kara
Kara Sea
The Kara Sea is part of the Arctic Ocean north of Siberia. It is separated from the Barents Sea to the west by the Kara Strait and Novaya Zemlya, and the Laptev Sea to the east by the Severnaya Zemlya....
, Laptev
Laptev Sea
The Laptev Sea is a marginal sea of the Arctic Ocean. It is located between the northern coast of Siberia, the Taimyr Peninsula, Severnaya Zemlya and the New Siberian Islands. Its northern boundary passes from the Arctic Cape to a point with co-ordinates of 79°N and 139°E, and ends at the Anisiy...
and East Siberian sea
East Siberian Sea
The East Siberian Sea is a marginal sea in the Arctic Ocean. It is located between the Arctic Cape to the north, the coast of Siberia to the south, the New Siberian Islands to the west and Cape Billings, close to Chukotka, and Wrangel Island to the east...
s, including the Ob
Ob River
The Ob River , also Obi, is a major river in western Siberia, Russia and is the world's seventh longest river. It is the westernmost of the three great Siberian rivers that flow into the Arctic Ocean .The Gulf of Ob is the world's longest estuary.-Names:The Ob is known to the Khanty people as the...
, Yenisei
Yenisei River
Yenisei , also written as Yenisey, is the largest river system flowing to the Arctic Ocean. It is the central of the three great Siberian rivers that flow into the Arctic Ocean...
(which drains Lake Baikal
Lake Baikal
Lake Baikal is the world's oldest at 30 million years old and deepest lake with an average depth of 744.4 metres.Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the...
via the Angara River
Angara River
The Angara River is a long river in Irkutsk Oblast and Krasnoyarsk Krai, south-east Siberia, Russia. It is the only river flowing out of Lake Baikal, and is the headwater tributary of the Yenisei River....
) the Lena
Lena River
The Lena is the easternmost of the three great Siberian rivers that flow into the Arctic Ocean . It is the 11th longest river in the world and has the 9th largest watershed...
and Kolyma river
Kolyma River
The Kolyma River is a river in northeastern Siberia, whose basin covers parts of the Sakha Republic, Chukotka Autonomous Okrug, and Magadan Oblast of Russia. Itrises in the mountains north of Okhotsk and Magadan, in the area of and...
s. It is also found in Kazakhstan
Kazakhstan
Kazakhstan , officially the Republic of Kazakhstan, is a transcontinental country in Central Asia and Eastern Europe. Ranked as the ninth largest country in the world, it is also the world's largest landlocked country; its territory of is greater than Western Europe...
and China
China
Chinese civilization may refer to:* China for more general discussion of the country.* Chinese culture* Greater China, the transnational community of ethnic Chinese.* History of China* Sinosphere, the area historically affected by Chinese culture...
in the Irtysh River, a major tributary of the Ob.
Taxonomy
Siberian sturgeon is typically subdivided into two subspeciesSubspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...
However, recent studies suggest that Siberian sturgeon may be monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...
, forming continuous genetically connected populations throughout their vast range.
The nominate taxon
Taxon
|thumb|270px|[[African elephants]] form a widely-accepted taxon, the [[genus]] LoxodontaA taxon is a group of organisms, which a taxonomist adjudges to be a unit. Usually a taxon is given a name and a rank, although neither is a requirement...
(A. baerii baerii) accounts for 80% of all Siberian sturgeon and resides in the Ob river and its tributaries. This subspecies migrates to mouth of the Ob river during the winter due to seasonal oxygen deficiency in the Ob River, and swim thousands of kilometers upstream to spawn
Spawn (biology)
Spawn refers to the eggs and sperm released or deposited, usually into water, by aquatic animals. As a verb, spawn refers to the process of releasing the eggs and sperm, also called spawning...
.
The subspecies A. baerii baicalensis known as the Baikal sturgeon
Baikal sturgeon
The Baikal sturgeon, Acipenser baerii baicalensis, is a sturgeon indigenous to Lake Baikal in Siberia, Russia. It is a subspecies of the widely distributed Siberian sturgeon . It resides primarily in the northern end of the lake, making considerable movements along the shore, and migrating up the...
is a unique lake form found primarily in the northern end of Lake Baikal
Lake Baikal
Lake Baikal is the world's oldest at 30 million years old and deepest lake with an average depth of 744.4 metres.Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the...
and migrates up the Selenga River to spawn.
A third form, "A. baerii stenorrhynchus", resides in the eastern Siberian rivers and displays two life history patterns: a more abundant migratory one which swims considerable distances (sometimes thousands of kilometers) upstream from estuaries and deltas to spawn, and a non-migratory form. This form is now considered to be a junior synonym of A. b. baerii.
Description and population status
Siberian sturgeon usually weigh approximately 65 kg, with considerable variability between and within river basins. The maximum recorded weight was 210 kg. As with all other acipenserids, the Siberian sturgeon are long-lived (up to sixty years), and late to reach sexual maturity (males at 11-24 years, females at 20-28 years). They spawn in strong current main stemMain Stem
"Main Stem" is 1942 instrumental by Duke Ellington and His Famous Orchestra. Although recorded in 1942, the single would not be released until 1944 where it was Duke Ellington's last of four number one's on the Harlem Hit Parade. "Main Stem" would also peak at number twenty on the pop chart"Main...
river channels on stone or gravel substrates.
The Siberian sturgeon feeds on a variety of benthic organisms such as crustaceans and chironomid larvae.
The species had been in steep decline in its natural range due to habitat loss, degradation and poaching
Poaching
Poaching is the illegal taking of wild plants or animals contrary to local and international conservation and wildlife management laws. Violations of hunting laws and regulations are normally punishable by law and, collectively, such violations are known as poaching.It may be illegal and in...
. Up to 40% of the Siberian sturgeon spawning habitat has been made inaccessible by damming. High levels of pollution
Water pollution
Water pollution is the contamination of water bodies . Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds....
in certain places has led to significant negative impacts on the reproductive development of gonads.
Aquaculture
While wild catches of Siberian sturgeon have been generally declining, the Siberian sturgeon is increasingly farmedAquaculture
Aquaculture, also known as aquafarming, is the farming of aquatic organisms such as fish, crustaceans, molluscs and aquatic plants. Aquaculture involves cultivating freshwater and saltwater populations under controlled conditions, and can be contrasted with commercial fishing, which is the...
both for meat and to produce caviar
Caviar
Caviar, sometimes called black caviar, is a luxury delicacy, consisting of processed, salted, non-fertilized sturgeon roe. The roe can be "fresh" or pasteurized, the latter having much less culinary and economic value....
from its roe
Roe
Roe or hard roe is the fully ripe internal egg masses in the ovaries, or the released external egg masses of fish and certain marine animals, such as shrimp, scallop and sea urchins...
. Because the Lena population of A. baerii completes its life cycle in freshwater and sexually matures relatively early, it is the most commonly original broodstock
Broodstock
Broodstock, or broodfish, are a group of mature individuals used in aquaculture for breeding purposes. Broodstock can be a population of animals maintained in captivity as a source of replacement for, or enhancement of, seed and fry numbers. These are generally kept in ponds or tanks in which...
for captive bred specimens. The main producer of Siberian sturgeon caviar is France
France
The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...
, while the largest meat producers are Russia and China.
Sources and links
- G. I. Ruban, Siberian Sturgeon Acipenser baerii Brandt (Species Structure and Ecology) (GEOS, Moscow, 1999) [in Russian].
- Acipenser baerii - IUCN assessment
- CITES Siberian Sturgeon (Acipenser baerii)
- FAO fact page on Acipenser baerii aquaculture.