Sturgeon
Encyclopedia
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 names, notably sterlet
, kaluga
and beluga
. Collectively, the family is also known as the True Sturgeons. Sturgeon is sometimes used more exclusively to refer to the species in the two best-known genera; Acipenser and Huso.
One of the oldest families of bony fish in existence, sturgeon are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia
and North America
. They are distinctive for their elongated bodies, lack of scales, and occasional great size: Sturgeons ranging from 7–12 feet (2-3½ m) in length are common, and some species grow up to 18 feet (5.5 m). Most sturgeons are anadromous bottom-feeders
, spawning upstream and feeding in river deltas and estuaries. While some are entirely freshwater, very few venture into the open ocean beyond near coastal areas.
Several species of sturgeons are harvested for their roe
, which is made into caviar
—a luxury food
which makes some sturgeons pound for pound the most valuable of all harvested fish. Because they are slow-growing and mature very late in life, they are particularly vulnerable to exploitation and to other threats, including pollution
and habitat fragmentation
. Most species of sturgeons are currently considered to be at risk of extinction
, making them more critically endangered than any other group of species.
appeared in the fossil record approximately 200 million years ago, making them among the most ancient of actinopterygian fishes. In that time they have undergone remarkably little morphological
change, indicating that their evolution has been exceptionally slow and earning them informal status as living fossils. This is explained in part by the long inter-generation time, tolerance for wide ranges of temperature
and salinity
, lack of predators
due to size, and the abundance of prey items in the benthic environment.
Despite the existence of a fossil
record, it has been difficult to fully classify the sturgeon species or unambiguously determine their phylogeny. This is in part due to the high individual and ontogenic
variation, including geographical clines in certain features, such as rostrum shape, number of scutes and body length. A further confounding factor is the peculiar ability of sturgeons to produce reproductively viable hybrids, even between species assigned to different genera
. The wide range of the Acipenserids and their endangered status have made collection of systematic materials difficult. These factors have led researchers in the past to identify over 40 additional species that were rejected by later workers. It is still unclear whether the species in the Acipenser and Huso genera are monophyletic (descended from one ancestor) or paraphyletic (descended from many ancestors)—though it is clear that the morphologically motivated division between these two genera is not supported by the genetic evidence. There is an ongoing effort to resolve the taxonomic confusion using a continuing synthesis of systematic data and molecular techniques
.
Chondrostei
, sturgeon are primarily cartilaginous, lack vertebral centra
, and are partially covered with bony plates called scutes rather than scales
. They also have four barbels—tactile organs that precede their toothless mouth and are dragged along often murky river bottoms
. Sturgeon are distinctly and immediately recognizable for their elongated bodies, flattened rostra
, distinctive scutes and barbels, and elongated upper tail lobes.
They are primarily benthic feeders. With their projecting wedge-shaped snout they stir up the soft bottom, and use the barbels to detect shells, crustaceans and small fish, on which they feed. Having no teeth, they are unable to seize prey, though larger specimens can swallow very large prey items, including whole salmon
.
Sturgeon have been referred to as both the Leviathan
s and Methuselah
s of freshwater fish. They are among the largest fish: some beluga
(Huso huso) in the Caspian Sea
reportedly attain over 5.5 m (18 ft.) and 2000 kg (4400 lbs.) while for kaluga
(H. dauricus) in the Amur River similar lengths and over 1000 kg (2200 lbs.) weights have been reported. They are also probably the longest-lived of the fishes, some living well over 100 years and attaining sexual maturity at 20 years or more. The combination of slow growth and reproductive rates and the extremely high value placed on mature egg-bearing females make sturgeon particularly vulnerable to overfishing
.
Sturgeons are polyploid
; some species have 4, 8, or 16 sets of chromosomes.
waters in North America
and Eurasia
. In North America
, they range along the Atlantic coast from the Gulf of Mexico
to Newfoundland, including the Great Lakes
and the St. Lawrence
, Missouri
and Mississippi
rivers, as well as along the West coast in major rivers from California
to British Columbia
. They occur along the European Atlantic coast, including the Mediterranean basin, in the rivers that flow into the Black
, Azov and Caspian
seas (Danube
, Dnepr, Volga and Don
), the north-flowing rivers of Russia that feed the Arctic Ocean
(Ob
, Yenisei, Lena
, Kolyma
), in the rivers of Central Asia
(Amu Darya
and Syr Darya
) and Lake Baikal
. In the Pacific Ocean, they are found in the Amur River along the Russian-Chinese
border, on Sakhalin
island, and in the Yangtze and other rivers in northeast China.
Throughout this extensive range, almost all species are highly threatened or vulnerable to extinction due to a combination of habitat destruction, overfishing and pollution.
No species are known to naturally occur south of the equator, though attempts at sturgeon aquaculture
are being made in Uruguay
, South Africa
and other places.
Most species are at least partially anadromous, spawning
in fresh water and feeding in nutrient rich brackish waters of estuaries or undergoing significant migrations along coastlines. However, some species have evolved purely freshwater existences, such as the lake sturgeon
(Acipenser fulvescens) and the Baikal sturgeon
(A. baerii baicalensis), or have been forced into them by anthropogenic or natural impoundment
of their native rivers, as in the case of some subpopulations of white sturgeon
(A. transmontanus) in the Columbia River
and Siberian sturgeon
(A. baerii) in the Ob basin.
, poaching
, water pollution and damming of rivers. According to the IUCN, over 85% of sturgeon species are classified as at risk of extinction, making them more critically endangered than any other group of species.
Globally, sturgeon fisheries are of great value primarily as a source for caviar
but also for its meat.
Before 1800, swim bladders of sturgeon (primarily Beluga sturgeon from Russia) were used as a source of isinglass
, a form of collagen used historically for the clarification of beer
, as a predecessor for gelatin
, and to preserve parchments.
The Jewish law of kashrut
, which only permits the consumption of fish with scales, forbids sturgeon, as they have ganoid scales instead of the permitted ctenoid and cycloid scales. While all Orthodox groups
forbid the consumption of sturgeon, some conservative groups
do allow it. The theological debate over its kosher status can be traced back to such 19th-century reformers as Aron Chorin, though its consumption was already common in European Jewish communities. It remains a high-end staple of many Jewish delis and specialty shops, such as Barney Greengrass
in New York City.
, the family Acipenseridae is subdivided into two subfamilies, Acipenserinae, including the genera Acipenser and Huso, and Scaphirhynchinae, including the genera Scaphirhynchus and Pseudosaphirhynchus.
Common name
A common name of a taxon or organism is a name in general use within a community; it is often contrasted with the scientific name for the same organism...
used for some 26 species of fish in the family Acipenseridae, including the genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
Acipenser
Acipenser
Acipenser is genus of sturgeons. With about 19 species, many of which are threatened, it is the largest genus in the order Acipenseriformes.-Species:*Acipenser baerii J. F. Brandt, 1869**Acipenser baerii baerii J. F...
, Huso
Huso
Huso is a genus of large sturgeons. It contains two species:*Huso dauricus *Huso huso...
, Scaphirhynchus
Scaphirhynchus
Scaphirhynchus is a genus of threatened sturgeons native to the United States of America. It contains three species:*Scaphirhynchus albus...
and Pseudoscaphirhynchus
Pseudoscaphirhynchus
Pseudoscaphirhynchus is a genus of fish in the Acipenseridae family. The three species, all of which are threatened, are restricted to west-central Asia.-Species:*Pseudoscaphirhynchus fedtschenkoi...
. The term includes over 20 species commonly referred to as sturgeon and several closely related species that have distinct common names, notably sterlet
Sterlet
The sterlet is a common Eurasian species of sturgeon, one of the smaller species of sturgeon. It is a common domestic species in the UK and Europe and an angling species all over the world...
, kaluga
Kaluga (fish)
The Kaluga is a large predatory sturgeon found in the Amur River basin. Also known as the River Beluga, they are claimed to be the largest freshwater fish in the world, with a maximum size of at least 1,000 kg and 5.6 m . Like the slightly larger Beluga, it spends part of its life in...
and beluga
Beluga sturgeon
The beluga or European sturgeon is a species of anadromous fish in the sturgeon family of order Acipenseriformes. It is found primarily in the Caspian and Black Sea basins, and occasionally in the Adriatic Sea...
. Collectively, the family is also known as the True Sturgeons. Sturgeon is sometimes used more exclusively to refer to the species in the two best-known genera; Acipenser and Huso.
One of the oldest families of bony fish in existence, sturgeon are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
and North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
. They are distinctive for their elongated bodies, lack of scales, and occasional great size: Sturgeons ranging from 7–12 feet (2-3½ m) in length are common, and some species grow up to 18 feet (5.5 m). Most sturgeons are anadromous bottom-feeders
Benthos
Benthos is the community of organisms which live on, in, or near the seabed, also known as the benthic zone. This community lives in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.Many organisms...
, spawning upstream and feeding in river deltas and estuaries. While some are entirely freshwater, very few venture into the open ocean beyond near coastal areas.
Several species of sturgeons are harvested for their 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...
, which is made into 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....
—a luxury food
Luxury good
Luxury goods are products and services that are not considered essential and associated with affluence.The concept of luxury has been present in various forms since the beginning of civilization. Its role was just as important in ancient western and eastern empires as it is in modern societies...
which makes some sturgeons pound for pound the most valuable of all harvested fish. Because they are slow-growing and mature very late in life, they are particularly vulnerable to exploitation and to other threats, including pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
and habitat fragmentation
Habitat fragmentation
Habitat fragmentation as the name implies, describes the emergence of discontinuities in an organism's preferred environment , causing population fragmentation...
. Most species of sturgeons are currently considered to be at risk of extinction
Critically endangered
Version 2010.3 of the IUCN Red List of Threatened Species identified 3744 Critically Endangered species, subspecies and varieties, stocks and subpopulations.Critically Endangered by kingdom:*1993 Animalia*2 Fungi*1745 Plantae*4 Protista-References:...
, making them more critically endangered than any other group of species.
Evolution
Sturgeon and related paddlefishPaddlefish
Paddlefish are primitive Chondrostean ray-finned fishes. The paddlefish can be distinguished by its large mouth and its elongated, spatula-like snout, called a rostrum, which is longer than the rest of the head...
appeared in the fossil record approximately 200 million years ago, making them among the most ancient of actinopterygian fishes. In that time they have undergone remarkably little morphological
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
change, indicating that their evolution has been exceptionally slow and earning them informal status as living fossils. This is explained in part by the long inter-generation time, tolerance for wide ranges of temperature
Temperature
Temperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
and salinity
Salinity
Salinity is the saltiness or dissolved salt content of a body of water. It is a general term used to describe the levels of different salts such as sodium chloride, magnesium and calcium sulfates, and bicarbonates...
, lack of predators
Predation
In ecology, predation describes a biological interaction where a predator feeds on its prey . Predators may or may not kill their prey prior to feeding on them, but the act of predation always results in the death of its prey and the eventual absorption of the prey's tissue through consumption...
due to size, and the abundance of prey items in the benthic environment.
Despite the existence of a fossil
Fossil
Fossils are the preserved remains or traces of animals , plants, and other organisms from the remote past...
record, it has been difficult to fully classify the sturgeon species or unambiguously determine their phylogeny. This is in part due to the high individual and ontogenic
Ontogeny
Ontogeny is the origin and the development of an organism – for example: from the fertilized egg to mature form. It covers in essence, the study of an organism's lifespan...
variation, including geographical clines in certain features, such as rostrum shape, number of scutes and body length. A further confounding factor is the peculiar ability of sturgeons to produce reproductively viable hybrids, even between species assigned to different genera
Genera
Genera is a commercial operating system and development environment for Lisp machines developed by Symbolics. It is essentially a fork of an earlier operating system originating on the MIT AI Lab's Lisp machines which Symbolics had used in common with LMI and Texas Instruments...
. The wide range of the Acipenserids and their endangered status have made collection of systematic materials difficult. These factors have led researchers in the past to identify over 40 additional species that were rejected by later workers. It is still unclear whether the species in the Acipenser and Huso genera are monophyletic (descended from one ancestor) or paraphyletic (descended from many ancestors)—though it is clear that the morphologically motivated division between these two genera is not supported by the genetic evidence. There is an ongoing effort to resolve the taxonomic confusion using a continuing synthesis of systematic data and molecular techniques
Genetics
Genetics , a discipline of biology, is the science of genes, heredity, and variation in living organisms....
.
Physical characteristics
Along with other members of the subclassSubclass
Subclass may refer to:* Subclass , a taxonomic rank intermediate between class and superorder* Subclass , a class that is derived from another class or classes...
Chondrostei
Chondrostei
Chondrostei are primarily cartilaginous fish showing some ossification. There are 52 species divided among two orders, the Acipenseriformes and the Polypteriformes ....
, sturgeon are primarily cartilaginous, lack vertebral centra
Body of vertebra
The body is the largest part of a vertebra, and is more or less cylindrical in shape. For vertebrates other than humans, this structure is usually called a centrum....
, and are partially covered with bony plates called scutes rather than scales
Scale (zoology)
In most biological nomenclature, a scale is a small rigid plate that grows out of an animal's skin to provide protection. In lepidopteran species, scales are plates on the surface of the insect wing, and provide coloration...
. They also have four barbels—tactile organs that precede their toothless mouth and are dragged along often murky river bottoms
Benthos
Benthos is the community of organisms which live on, in, or near the seabed, also known as the benthic zone. This community lives in or near marine sedimentary environments, from tidal pools along the foreshore, out to the continental shelf, and then down to the abyssal depths.Many organisms...
. Sturgeon are distinctly and immediately recognizable for their elongated bodies, flattened rostra
Rostrum (anatomy)
The term rostrum is used for a number of unrelated structures in different groups of animals:*In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes....
, distinctive scutes and barbels, and elongated upper tail lobes.
They are primarily benthic feeders. With their projecting wedge-shaped snout they stir up the soft bottom, and use the barbels to detect shells, crustaceans and small fish, on which they feed. Having no teeth, they are unable to seize prey, though larger specimens can swallow very large prey items, including whole salmon
Salmon
Salmon is the common name for several species of fish in the family Salmonidae. Several other fish in the same family are called trout; the difference is often said to be that salmon migrate and trout are resident, but this distinction does not strictly hold true...
.
Sturgeon have been referred to as both the Leviathan
Leviathan
Leviathan , is a sea monster referred to in the Bible. In Demonology, Leviathan is one of the seven princes of Hell and its gatekeeper . The word has become synonymous with any large sea monster or creature...
s and Methuselah
Methuselah
Methuselah is the oldest person whose age is mentioned in the Hebrew Bible. Extra-biblical tradition maintains that he died on the 11th of Cheshvan of the year 1656 , at the age of 969, seven days before the beginning of the Great Flood...
s of freshwater fish. They are among the largest fish: some beluga
Beluga sturgeon
The beluga or European sturgeon is a species of anadromous fish in the sturgeon family of order Acipenseriformes. It is found primarily in the Caspian and Black Sea basins, and occasionally in the Adriatic Sea...
(Huso huso) in the Caspian Sea
Caspian Sea
The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...
reportedly attain over 5.5 m (18 ft.) and 2000 kg (4400 lbs.) while for kaluga
Kaluga (fish)
The Kaluga is a large predatory sturgeon found in the Amur River basin. Also known as the River Beluga, they are claimed to be the largest freshwater fish in the world, with a maximum size of at least 1,000 kg and 5.6 m . Like the slightly larger Beluga, it spends part of its life in...
(H. dauricus) in the Amur River similar lengths and over 1000 kg (2200 lbs.) weights have been reported. They are also probably the longest-lived of the fishes, some living well over 100 years and attaining sexual maturity at 20 years or more. The combination of slow growth and reproductive rates and the extremely high value placed on mature egg-bearing females make sturgeon particularly vulnerable to overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
.
Sturgeons are polyploid
Polyploidy
Polyploid is a term used to describe cells and organisms containing more than two paired sets of chromosomes. Most eukaryotic species are diploid, meaning they have two sets of chromosomes — one set inherited from each parent. However polyploidy is found in some organisms and is especially common...
; some species have 4, 8, or 16 sets of chromosomes.
Range and habitat
Sturgeon range from subtropical to subarcticSubarctic
The Subarctic is a region in the Northern Hemisphere immediately south of the true Arctic and covering much of Alaska, Canada, the north of Scandinavia, Siberia, and northern Mongolia...
waters in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
and Eurasia
Eurasia
Eurasia is a continent or supercontinent comprising the traditional continents of Europe and Asia ; covering about 52,990,000 km2 or about 10.6% of the Earth's surface located primarily in the eastern and northern hemispheres...
. In North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...
, they range along the Atlantic coast from the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
to Newfoundland, including the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...
and the St. Lawrence
Saint Lawrence River
The Saint Lawrence is a large river flowing approximately from southwest to northeast in the middle latitudes of North America, connecting the Great Lakes with the Atlantic Ocean. It is the primary drainage conveyor of the Great Lakes Basin...
, Missouri
Missouri River
The Missouri River flows through the central United States, and is a tributary of the Mississippi River. It is the longest river in North America and drains the third largest area, though only the thirteenth largest by discharge. The Missouri's watershed encompasses most of the American Great...
and Mississippi
Mississippi
Mississippi is a U.S. state located in the Southern United States. Jackson is the state capital and largest city. The name of the state derives from the Mississippi River, which flows along its western boundary, whose name comes from the Ojibwe word misi-ziibi...
rivers, as well as along the West coast in major rivers from California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
to British Columbia
British Columbia
British Columbia is the westernmost of Canada's provinces and is known for its natural beauty, as reflected in its Latin motto, Splendor sine occasu . Its name was chosen by Queen Victoria in 1858...
. They occur along the European Atlantic coast, including the Mediterranean basin, in the rivers that flow into the Black
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...
, Azov and Caspian
Caspian Sea
The Caspian Sea is the largest enclosed body of water on Earth by area, variously classed as the world's largest lake or a full-fledged sea. The sea has a surface area of and a volume of...
seas (Danube
Danube
The Danube is a river in the Central Europe and the Europe's second longest river after the Volga. It is classified as an international waterway....
, Dnepr, Volga and Don
Don River (Russia)
The Don River is one of the major rivers of Russia. It rises in the town of Novomoskovsk 60 kilometres southeast from Tula, southeast of Moscow, and flows for a distance of about 1,950 kilometres to the Sea of Azov....
), the north-flowing rivers of Russia that feed the Arctic Ocean
Arctic Ocean
The Arctic Ocean, located in the Northern Hemisphere and mostly in the Arctic north polar region, is the smallest and shallowest of the world's five major oceanic divisions...
(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, 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...
, Kolyma
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...
), in the rivers of Central Asia
Central Asia
Central Asia is a core region of the Asian continent from the Caspian Sea in the west, China in the east, Afghanistan in the south, and Russia in the north...
(Amu Darya
Amu Darya
The Amu Darya , also called Oxus and Amu River, is a major river in Central Asia. It is formed by the junction of the Vakhsh and Panj rivers...
and Syr Darya
Syr Darya
The Syr Darya , also transliterated Syrdarya or Sirdaryo, is a river in Central Asia, sometimes known as the Jaxartes or Yaxartes from its Ancient Greek name . The Greek name is derived from Old Persian, Yakhsha Arta , a reference to the color of the river's water...
) and 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...
. In the Pacific Ocean, they are found in the Amur River along the Russian-Chinese
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...
border, on Sakhalin
Sakhalin
Sakhalin or Saghalien, is a large island in the North Pacific, lying between 45°50' and 54°24' N.It is part of Russia, and is Russia's largest island, and is administered as part of Sakhalin Oblast...
island, and in the Yangtze and other rivers in northeast China.
Throughout this extensive range, almost all species are highly threatened or vulnerable to extinction due to a combination of habitat destruction, overfishing and pollution.
No species are known to naturally occur south of the equator, though attempts at sturgeon aquaculture
Aquaculture
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...
are being made in Uruguay
Uruguay
Uruguay ,officially the Oriental Republic of Uruguay,sometimes the Eastern Republic of Uruguay; ) is a country in the southeastern part of South America. It is home to some 3.5 million people, of whom 1.8 million live in the capital Montevideo and its metropolitan area...
, South Africa
South Africa
The Republic of South Africa is a country in southern Africa. Located at the southern tip of Africa, it is divided into nine provinces, with of coastline on the Atlantic and Indian oceans...
and other places.
Most species are at least partially anadromous, spawning
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...
in fresh water and feeding in nutrient rich brackish waters of estuaries or undergoing significant migrations along coastlines. However, some species have evolved purely freshwater existences, such as the lake sturgeon
Lake sturgeon
The lake sturgeon is a North American temperate freshwater fish, one of about 20 species of sturgeon. Like other sturgeons, this species is an evolutionarily ancient bottomfeeder with a partly cartilaginous skeleton and skin bearing rows of bony plates...
(Acipenser fulvescens) and 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...
(A. baerii baicalensis), or have been forced into them by anthropogenic or natural impoundment
Dam
A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...
of their native rivers, as in the case of some subpopulations of white sturgeon
White sturgeon
The white sturgeon , also known as the Pacific sturgeon, Oregon sturgeon, Columbia sturgeon, Sacramento sturgeon, and California white sturgeon, is a sturgeon which lives along the west coast of North America from the Aleutian Islands to Central...
(A. transmontanus) in the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...
and Siberian sturgeon
Siberian sturgeon
The Siberian sturgeon is a species of sturgeon in the Acipenseridae family. It is most present in all of the major Siberian river basins that drain northward into the Kara, Laptev and East Siberian seas, including the Ob, Yenisei the Lena and Kolyma rivers...
(A. baerii) in the Ob basin.
Conservation status
Because of their long reproductive cycle, long migrations, and sensitivity to environmental conditions, many species are under severe threat from overfishingOverfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
, 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...
, water pollution and damming of rivers. According to the IUCN, over 85% of sturgeon species are classified as at risk of extinction, making them more critically endangered than any other group of species.
Uses
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....
but also for its meat.
Before 1800, swim bladders of sturgeon (primarily Beluga sturgeon from Russia) were used as a source of isinglass
Isinglass
Isinglass is a substance obtained from the dried swim bladders of fish. It is a form of collagen used mainly for the clarification of wine and beer. It can also be cooked into a paste for specialized gluing purposes....
, a form of collagen used historically for the clarification of beer
Beer
Beer is the world's most widely consumed andprobably oldest alcoholic beverage; it is the third most popular drink overall, after water and tea. It is produced by the brewing and fermentation of sugars, mainly derived from malted cereal grains, most commonly malted barley and malted wheat...
, as a predecessor for gelatin
Gelatin
Gelatin is a translucent, colorless, brittle , flavorless solid substance, derived from the collagen inside animals' skin and bones. It is commonly used as a gelling agent in food, pharmaceuticals, photography, and cosmetic manufacturing. Substances containing gelatin or functioning in a similar...
, and to preserve parchments.
The Jewish law of kashrut
Kashrut
Kashrut is the set of Jewish dietary laws. Food in accord with halakha is termed kosher in English, from the Ashkenazi pronunciation of the Hebrew term kashér , meaning "fit" Kashrut (also kashruth or kashrus) is the set of Jewish dietary laws. Food in accord with halakha (Jewish law) is termed...
, which only permits the consumption of fish with scales, forbids sturgeon, as they have ganoid scales instead of the permitted ctenoid and cycloid scales. While all Orthodox groups
Orthodox Judaism
Orthodox Judaism , is the approach to Judaism which adheres to the traditional interpretation and application of the laws and ethics of the Torah as legislated in the Talmudic texts by the Sanhedrin and subsequently developed and applied by the later authorities known as the Gaonim, Rishonim, and...
forbid the consumption of sturgeon, some conservative groups
Conservative Judaism
Conservative Judaism is a modern stream of Judaism that arose out of intellectual currents in Germany in the mid-19th century and took institutional form in the United States in the early 1900s.Conservative Judaism has its roots in the school of thought known as Positive-Historical Judaism,...
do allow it. The theological debate over its kosher status can be traced back to such 19th-century reformers as Aron Chorin, though its consumption was already common in European Jewish communities. It remains a high-end staple of many Jewish delis and specialty shops, such as Barney Greengrass
Barney Greengrass
Barney Greengrass is a restaurant and appetizing store on the Upper West Side of Manhattan that was started in 1908. They specialize in sturgeon, Nova Scotia salmon, and whitefish. They were the winner of the 2006 James Beard Foundation Award for Excellence....
in New York City.
Species
In currently accepted taxonomyTaxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...
, the family Acipenseridae is subdivided into two subfamilies, Acipenserinae, including the genera Acipenser and Huso, and Scaphirhynchinae, including the genera Scaphirhynchus and Pseudosaphirhynchus.
- Family Acipenseridae BonaparteCharles Lucien BonaparteCharles Lucien Jules Laurent Bonaparte, 2nd Prince of Canino and Musignano was a French naturalist and ornithologist.-Biography:...
, 1831- Subfamily Acipenserinae
- Genus AcipenserAcipenserAcipenser is genus of sturgeons. With about 19 species, many of which are threatened, it is the largest genus in the order Acipenseriformes.-Species:*Acipenser baerii J. F. Brandt, 1869**Acipenser baerii baerii J. F...
Linnaeus, 1758- Acipenser baerii J. F. BrandtJohann Friedrich von BrandtJohann Friedrich von Brandt was a German naturalist.Brandt was born in Jüterbog and educated at a gymnasium in Wittenberg and the University of Berlin. In 1831 he was appointed director of the Zoological Department at the St Petersburg Academy of Sciences, where he published in Russian...
, 1869- Acipenser baerii baerii J. F. Brandt, 1869 (Siberian sturgeon)
- Acipenser baerii baicalensis NikolskiiAlexander Mikhailovich NikolskyAlexander Mikhailovich Nikolsky was a Russian zoologist born in Astrakhan.From 1877 to 1881 he studied at the University of St. Petersburg, earning his doctorate several years later in 1887. From 1881 to 1891 he took part in numerous expeditions to Siberia, the Caucasus, Persia, Japan, et al. In...
, 1896 (Baikal sturgeon)
- Acipenser brevirostrum LesueurCharles Alexandre LesueurCharles Alexandre Lesueur was a French naturalist, artist and explorer.Pictured here is the oil portrait by Charles Willson Peale of Charles-Alexandre Lesueur...
, 1818 (Shortnose sturgeon) - Acipenser colchicus Marti, 1940 (Black Sea sturgeon)
- Acipenser dabryanus A. H. A. Duméril, 1869 (Yangtze sturgeon)
- Acipenser fulvescens Rafinesque (Lake sturgeon)
- Acipenser gueldenstaedtii J. F. BrandtJohann Friedrich von BrandtJohann Friedrich von Brandt was a German naturalist.Brandt was born in Jüterbog and educated at a gymnasium in Wittenberg and the University of Berlin. In 1831 he was appointed director of the Zoological Department at the St Petersburg Academy of Sciences, where he published in Russian...
& RatzeburgJulius Theodor Christian RatzeburgJulius Theodor Christian Ratzeburg was a German zoologist, botanist, entomologist, and forester.-Biography:...
, 1833 (Russian sturgeon) - Acipenser medirostris AyresWilliam Orville AyresWilliam Orville Ayres was an American physician and ichthyologist. Born in Connecticut, he studied to become a doctor at Yale University School of Medicine....
, 1854 (Green sturgeon) - Acipenser mikadoi HilgendorfFranz Martin HilgendorfFranz Martin Hilgendorf was a German zoologist and paleontologist. Hilgendorf's research on fossil snails from the Steinheim crater in the early 1860s became a palaeontological evidence for the theory of evolution published by Charles Darwin in 1859.-Life and work:Franz Hilgendorf was born...
, 1892 (Sakhalin sturgeon) - Acipenser multiscutatus S. Tanaka (I)Shigeho Tanakawas a Japanese ichthyologist and professor of zoology at the Imperial University of Tokyo. He published numerous works on fishes and sharks and co-authored a book on Japanese fish with famous American scientist David Starr Jordan.Publications:...
, 1908 (Japanese sturgeon) - Acipenser naccarii BonaparteCharles Lucien BonaparteCharles Lucien Jules Laurent Bonaparte, 2nd Prince of Canino and Musignano was a French naturalist and ornithologist.-Biography:...
, 1836 (Adriatic sturgeon) - Acipenser nudiventris Lovetsky, 1828 (Fringebarbel sturgeon)
- Acipenser oxyrinchus Mitchill, 1815
- Acipenser oxyrinchus desotoi Vladykov, 1955 (Gulf sturgeon)
- Acipenser oxyrinchus oxyrinchus Mitchill, 1815 (Atlantic sturgeon)
- Acipenser persicus Borodin, 1897 (Persian sturgeon)
- Acipenser ruthenus Linnaeus, 1758 (Sterlet)
- Acipenser schrenckii J. F. BrandtJohann Friedrich von BrandtJohann Friedrich von Brandt was a German naturalist.Brandt was born in Jüterbog and educated at a gymnasium in Wittenberg and the University of Berlin. In 1831 he was appointed director of the Zoological Department at the St Petersburg Academy of Sciences, where he published in Russian...
, 1869 (Amur sturgeon) - Acipenser sinensis J. E. GrayJohn Edward GrayJohn Edward Gray, FRS was a British zoologist. He was the elder brother of George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray ....
, 1835 (Chinese sturgeon) - Acipenser stellatus PallasPeter Simon PallasPeter Simon Pallas was a German zoologist and botanist who worked in Russia.- Life and work :Pallas was born in Berlin, the son of Professor of Surgery Simon Pallas. He studied with private tutors and took an interest in natural history, later attending the University of Halle and the University...
, 1771 (Starry sturgeon) - Acipenser sturio Linnaeus, 1758 (European sturgeon)
- Acipenser transmontanus J. RichardsonJohn Richardson (naturalist)Sir John Richardson was a Scottish naval surgeon, naturalist and arctic explorer.Richardson was born at Dumfries. He studied medicine at Edinburgh University, and became a surgeon in the navy in 1807. He traveled with John Franklin in search of the Northwest Passage on the Coppermine Expedition of...
, 1836 (White sturgeon)
- Acipenser baerii J. F. Brandt
- Genus Huso J. F. BrandtJohann Friedrich von BrandtJohann Friedrich von Brandt was a German naturalist.Brandt was born in Jüterbog and educated at a gymnasium in Wittenberg and the University of Berlin. In 1831 he was appointed director of the Zoological Department at the St Petersburg Academy of Sciences, where he published in Russian...
& RatzeburgJulius Theodor Christian RatzeburgJulius Theodor Christian Ratzeburg was a German zoologist, botanist, entomologist, and forester.-Biography:...
, 1833- Huso dauricus (GeorgiJohann Gottlieb GeorgiJohann Gottlieb Georgi was a German geographer and chemist.Georgi was professor of chemistry at St Petersburg. He accompanied both Johann Peter Falck and Peter Simon Pallas on their respective journeys through Siberia. Gergi was particularly interested in Lake Baikal...
, 1775) (Kaluga sturgeon) - Huso huso (Linnaeus, 1758) (Beluga sturgeon)
- Huso dauricus (Georgi
- Genus Acipenser
- Subfamily ScaphirhynchinaeScaphirhynchinaeScaphirhynchinae is a subfamily of sturgeon which includes two genera comprising a total of six species.*Genus Scaphirhynchus Heckel, 1835 **Scaphirhynchus albus...
- Genus Scaphirhynchus HeckelJohann Jakob HeckelJohann Jakob Heckel was an Austrian taxidermist, zoologist, and ichthyologist from Mannheim.Though not a formally trained zoologist he worked his way up through the ranks to eventually become the director of the Fish Collection at the Naturhistorisches Museum in Vienna...
, 1835- Scaphirhynchus albus (ForbesStephen Alfred ForbesStephen Alfred Forbes was the first Chief of the Illinois Natural History Survey, a founder of aquatic ecosystem science and a dominant figure in the rise of American ecology. His publications are striking for their merger of extensive field observations with conceptual insights...
& R. E. Richardson, 1905) (Pallid sturgeon) - Scaphirhynchus platorynchus (Rafinesque, 1820) (Shovelnose sturgeon)
- Scaphirhynchus suttkusi J. D. Williams & Clemmer, 1991 (Alabama sturgeon)
- Scaphirhynchus albus (Forbes
- Genus Pseudoscaphirhynchus NikolskiiAlexander Mikhailovich NikolskyAlexander Mikhailovich Nikolsky was a Russian zoologist born in Astrakhan.From 1877 to 1881 he studied at the University of St. Petersburg, earning his doctorate several years later in 1887. From 1881 to 1891 he took part in numerous expeditions to Siberia, the Caucasus, Persia, Japan, et al. In...
, 1900- Pseudoscaphirhynchus fedtschenkoi (KesslerKarl Fedorovich KesslerKarl Fedorovich Kessler was a German-Russian zoologist and author of zoological taxa signed Kessler, who was mostly active in Kiev, Ukraine and conducted most of his studies of birds in Ukrainian regions of the Russian Empire - Kiev Governorate, Volyn Governorate, Kherson Governorate, Poltava...
, 1872) (Syr Darya sturgeon) - Pseudoscaphirhynchus hermanni (KesslerKarl Fedorovich KesslerKarl Fedorovich Kessler was a German-Russian zoologist and author of zoological taxa signed Kessler, who was mostly active in Kiev, Ukraine and conducted most of his studies of birds in Ukrainian regions of the Russian Empire - Kiev Governorate, Volyn Governorate, Kherson Governorate, Poltava...
, 1877) (Dwarf sturgeon) - Pseudoscaphirhynchus kaufmanni (KesslerKarl Fedorovich KesslerKarl Fedorovich Kessler was a German-Russian zoologist and author of zoological taxa signed Kessler, who was mostly active in Kiev, Ukraine and conducted most of his studies of birds in Ukrainian regions of the Russian Empire - Kiev Governorate, Volyn Governorate, Kherson Governorate, Poltava...
, 1877) (Amu Darya sturgeon)
- Pseudoscaphirhynchus fedtschenkoi (Kessler
- Genus Scaphirhynchus Heckel
- Subfamily Acipenserinae