Sturgeon (from
Old English
Old English ( or , or ), or Anglo-Saxon, is the earliest recorded form of the English language, spoken in England and southern and eastern Scotland in the Early Middle Ages. It developed from the languages brought to Great Britain by Anglo-S ...
ultimately from
Proto-Indo-European
Proto-Indo-European (PIE) is the reconstructed common ancestor of the Indo-European language family. No direct record of Proto-Indo-European exists; its proposed features have been derived by linguistic reconstruction from documented Indo-Euro ...
*''str̥(Hx)yón''-) is the
common name
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often con ...
for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...
, and are descended from other, earlier
acipenseriform fish, which date back to the
Early Jurassic
The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic� ...
period, some 174 to 201 million years ago. They are one of two living families of the Acipenseriformes alongside
paddlefish
Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their elongated rost ...
(Polyodontidae). The family is grouped into five genera: ''
Acipenser
''Acipenser'' is a genus of sturgeons, containing three species native to freshwater and estuarine systems of eastern North America and Europe. It is the type genus of the family Acipenseridae and the order Acipenseriformes.
Taxonomy
Prior t ...
'', ''
Huso
''Huso'' is a genus of sturgeons from eastern Europe, Asia, and eastern North America. The genus name is derived from ''wikt:huso, hūso'', the Old High German and Medieval Latin word for "sturgeon", which is also ancestral to ''wikt:Hausen, Haus ...
'', ''
Scaphirhynchus
''Scaphirhynchus'' is a genus of sturgeons native to North America. All species in this genus are considered to be Threatened species, threatened with extinction or worse. As of 2023, the pallid sturgeon (''S. albus'') and the Alabama sturgeon ( ...
,'' ''
Sinosturio'', and ''
Pseudoscaphirhynchus
''Pseudoscaphirhynchus'' is a genus of relatively small, highly threatened sturgeons that are restricted to the Aral Sea system (although Local extinction, extirpated from the Aral Sea itself), including the Amu Darya and Syr Darya river basins, ...
''.
Two species (''
H. naccarii'' and ''
S. dabryanus'') may be
extinct in the wild
A species that is extinct in the wild (EW) is one that has been categorized by the International Union for Conservation of Nature as only consisting of living members kept in captivity or as a naturalized population outside its historic range ...
, and one (''
P. fedtschenkoi'') may be entirely extinct.
Sturgeons are native to subtropical, temperate and sub-Arctic rivers, lakes and coastlines of
Eurasia
Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...
and
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
.
A
Maastrichtian
The Maastrichtian ( ) is, in the International Commission on Stratigraphy (ICS) geologic timescale, the latest age (geology), age (uppermost stage (stratigraphy), stage) of the Late Cretaceous epoch (geology), Epoch or Upper Cretaceous series (s ...
-age fossil found in
Morocco
Morocco, officially the Kingdom of Morocco, is a country in the Maghreb region of North Africa. It has coastlines on the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria to Algeria–Morocc ...
shows that they also once lived in northern
Africa
Africa is the world's second-largest and second-most populous continent after Asia. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 20% of Earth's land area and 6% of its total surfac ...
during the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
.
Sturgeons are long-lived, late-maturing fishes with distinctive characteristics, such as a
heterocercal caudal fin similar to those of
shark
Sharks are a group of elasmobranch cartilaginous fish characterized by a ribless endoskeleton, dermal denticles, five to seven gill slits on each side, and pectoral fins that are not fused to the head. Modern sharks are classified within the ...
s, and an elongated, spindle-like body that is smooth-skinned, scaleless, and armored with five lateral rows of bony plates called
scutes
A scute () or scutum (Latin: ''scutum''; plural: ''scuta'' "shield") is a bony external plate or scale overlaid with horn, as on the shell of a turtle, the skin of crocodilians, and the feet of birds. The term is also used to describe the anterio ...
. Several species can grow quite large, typically ranging in length. The largest sturgeon on record was a
beluga
Beluga may refer to:
Animals
*Beluga (sturgeon)
* Beluga whale
Vehicles
* Airbus Beluga, a large transport airplane
* Airbus BelugaXL, a larger transport airplane
* Beluga-class submarine, a class of Russian SSA diesel-electric submarine
* U ...
female captured in the
Volga Delta
The Volga Delta is the largest river delta in Europe and occurs where Europe's largest river system, the Volga River, drains into the Caspian Sea in Russia's Astrakhan Oblast, north-east of the republic of Kalmykia. The delta is located in the ...
in 1827, measuring long and weighing . Most sturgeons are
anadromous
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousa ...
bottom-feeders, migrating upstream to spawn but spending most of their lives feeding in
river delta
A river delta is a landform, archetypically triangular, created by the deposition of the sediments that are carried by the waters of a river, where the river merges with a body of slow-moving water or with a body of stagnant water. The creat ...
s and
estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...
. Some species inhabit freshwater environments exclusively, while others primarily inhabit marine environments near
coastal
A coast (coastline, shoreline, seashore) is the land next to the sea or the line that forms the boundary between the land and the ocean or a lake. Coasts are influenced by the topography of the surrounding landscape and by aquatic erosion, su ...
areas, and are known to venture into open ocean.
Several species of sturgeon are harvested for their
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, sea urchins and squid. As a seafood, roe is used both as a cooking, c ...
, which is processed into the
luxury food caviar
Caviar or caviare is a food consisting of salt-cured roe of the family Acipenseridae. Caviar is considered a delicacy and is eaten as a garnish or spread. Traditionally, the term caviar refers only to roe from wild sturgeon in the Caspi ...
. This has led to serious
overexploitation
Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to ...
, which combined with other conservation threats, has brought most of the species to
critically endangered
An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...
status, at the edge of
extinction
Extinction is the termination of an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce and ...
.
Evolution
Fossil history
Acipenseriform fishes appeared in the fossil record some 174 to 201 million years ago, during the
Early Jurassic
The Early Jurassic Epoch (geology), Epoch (in chronostratigraphy corresponding to the Lower Jurassic series (stratigraphy), Series) is the earliest of three epochs of the Jurassic Period. The Early Jurassic starts immediately after the Triassic� ...
, making them some of the earliest extant
actinopterygian fishes.
Sturgeons must have diverged from their closest relatives, the
paddlefish
Paddlefish (family Polyodontidae) are a family of ray-finned fish belonging to order Acipenseriformes, and one of two living groups of the order alongside sturgeons (Acipenseridae). They are distinguished from other fish by their elongated rost ...
, during the
Early Cretaceous
The Early Cretaceous (geochronology, geochronological name) or the Lower Cretaceous (chronostratigraphy, chronostratigraphic name) is the earlier or lower of the two major divisions of the Cretaceous. It is usually considered to stretch from 143.1 ...
(125-120 million years ago) or prior, as the earliest fossil paddlefish (''
Protopsephurus'') is known from then.
True sturgeons appear in the fossil record during the Upper
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
, with amongst the oldest known remains being a partial skull from the
Cenomanian
The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...
(100–94 million years ago) of Alberta, Canada.
In that time, sturgeons have undergone remarkably little
morphological change, indicating their evolution has been exceptionally slow and earning them informal status as
living fossils.
This is explained in part by the long generation interval, tolerance for wide ranges of
temperature
Temperature is a physical quantity that quantitatively expresses the attribute of hotness or coldness. Temperature is measurement, measured with a thermometer. It reflects the average kinetic energy of the vibrating and colliding atoms making ...
and
salinity
Salinity () is the saltiness or amount of salt (chemistry), salt dissolved in a body of water, called saline water (see also soil salinity). It is usually measured in g/L or g/kg (grams of salt per liter/kilogram of water; the latter is dimensio ...
, lack of
predators due to size and bony plated armor, or scutes, and the abundance of prey items in the benthic environment. They do, however, still share several primitive characteristics, such as heterocercal tail, reduced squamation, more fin rays than supporting bony elements, and unique jaw suspension.
Phylogeny and taxonomy
Despite the existence of a
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserve ...
record, full classification and
phylogeny
A phylogenetic tree or phylogeny is a graphical representation which shows the evolutionary history between a set of species or Taxon, taxa during a specific time.Felsenstein J. (2004). ''Inferring Phylogenies'' Sinauer Associates: Sunderland, M ...
of the sturgeon species has been difficult to determine, 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
Genus (; : genera ) is a taxonomic rank above species and below family as used in the biological classification of living and fossil organisms as well as viruses. In binomial nomenclature, the genus name forms the first part of the binomial s ...
. While ray-finned fishes (Actinopterygii) have a long evolutionary history culminating in the most familiar fishes, past adaptive
evolutionary radiation
An evolutionary radiation is an increase in taxonomic diversity that is caused by elevated rates of speciation, that may or may not be associated with an increase in morphological disparity. A significantly large and diverse radiation within ...
s have left only a few survivors, such as sturgeons and
gars.
The phylogeny of Acipenseridae, as in the
cladogram
A cladogram (from Greek language, Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an Phylogenetic tree, evolutionary tree because it does not s ...
, shows that they evolved from the
bony fishes. In currently accepted
taxonomy
image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy
Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme o ...
, the class
Actinopterygii
Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class (biology), class of Osteichthyes, bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built ...
and the order
Acipenseriformes
Acipenseriformes is an order (biology), order of basal (phylogenetics), basal Actinopterygii, ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct family (biology), families C ...
are both
clade
In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ...
s.
Approximate dates are from Near ''et al.'', 2012.
The wide range of the acipenserids and their endangered status have made collection of systematic materials difficult. The factors have led researchers in the past to identify over 40 additional species that were rejected by later scientists.
. An effort is ongoing to resolve the taxonomic confusion using a continuing synthesis of systematic data and
molecular techniques.
Sturgeons are a highly morphologically conservative group, to the extent that lineages that (based on molecular data) have been separate since the
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
period can physically appear very similar, and mistakenly classified as each others' closest relatives. In the classic taxonomic treatment, Acipenseridae was subdivided into 2 subfamilies;
Acipenserinae, including the genera ''
Acipenser
''Acipenser'' is a genus of sturgeons, containing three species native to freshwater and estuarine systems of eastern North America and Europe. It is the type genus of the family Acipenseridae and the order Acipenseriformes.
Taxonomy
Prior t ...
'' and ''
Huso
''Huso'' is a genus of sturgeons from eastern Europe, Asia, and eastern North America. The genus name is derived from ''wikt:huso, hūso'', the Old High German and Medieval Latin word for "sturgeon", which is also ancestral to ''wikt:Hausen, Haus ...
'', and
Scaphirhynchinae
Sturgeon (from Old English ultimately from Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the Late Cretaceous, and are desce ...
, including the genera ''
Scaphirhynchus
''Scaphirhynchus'' is a genus of sturgeons native to North America. All species in this genus are considered to be Threatened species, threatened with extinction or worse. As of 2023, the pallid sturgeon (''S. albus'') and the Alabama sturgeon ( ...
'' and ''
Pseudoscaphirhynchus
''Pseudoscaphirhynchus'' is a genus of relatively small, highly threatened sturgeons that are restricted to the Aral Sea system (although Local extinction, extirpated from the Aral Sea itself), including the Amu Darya and Syr Darya river basins, ...
''.
Under a phylogeny that exclusively incorporates morphological data, sturgeons appear to comprise two groups that diverged during the Cretaceous: a ''Scaphirhynchus'' lineage, and a ''Acipenser''+''Huso''+''Pseudoscaphirhynchus'' lineage. The latter seemingly appears rather young compared to the age of the group as a whole, with much of its radiation only occurring during the
Late Paleogene and
Neogene
The Neogene ( ,) is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period million years ago. It is the second period of th ...
.
However, with the advent of
molecular phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
, multiple studies since the 1990s have recovered this arrangement as
paraphyletic
Paraphyly is a taxonomic term describing a grouping that consists of the grouping's last common ancestor and some but not all of its descendant lineages. The grouping is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...
, instead finding ''
A. oxyrhinchus'' and ''
A. sturio'' to form the most
basal clade among sturgeons, and all other species being in a separate clade, with the various other species of ''Acipenser'', ''Scaphirhynchus'', ''Pseudoscaphirhynchus'', and ''Huso'' to have varying levels of relationship with one another. The morphologically distinct "shovelnose" type sturgeons are deeply nested within the former "''Acipenser''" and "''Huso''" clades. The divergences within the group have also been found to be much deeper, with ''Acipenser
sensu stricto
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...
'' diverging from the rest of the group well into the Cretaceous. The other lineages were found to have diverged from one another during the Late Cretaceous and Paleogene.
The exact placement of ''Scaphirhynchus'' varies depending on the study and the methods used, with some placing it within the second-most basal clade comprising primarily Pacific species, whereas others place it in its own clade that is more derived than the secondmost basal clade but less derived than the most derived Atlantic and Central Asian clade. No studies have yet delineated a relationship between it and ''Pseudoscaphirhynchus''. In addition, the exact relationships of the members of the most
derived, primarily Atlantic clade vary, although most analyses at least find all the species in it to form a monophyletic clade. The placement of ''A. sinensis'' also varies by the study, with some placing it as the only Pacific member of the otherwise Atlantic-based most-derived clade, whereas others place it with the rest of the Pacific sturgeons as a sister to ''A. dabryanus''.
Brownstein &
Near (2025) used DNA sequencing and morphological data to establish 5
monophyletic
In biological cladistics for the classification of organisms, monophyly is the condition of a taxonomic grouping being a clade – that is, a grouping of organisms which meets these criteria:
# the grouping contains its own most recent co ...
genera for Acipenseridae and mostly resolve the longstanding confusion over clade names. The 5 clades found were ''Acipenser
sensu stricto
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular c ...
'', ''Scaphirhynchus'', ''Pseudoscaphirhynchus'', ''Huso'', and the revived genus ''Sinosturio'', as well as moving species out of ''Acipenser'' and into the latter two genera (including the kaluga, now ''Sinosturio dauricus'').
The following taxonomy is based on Brownstein & Near, 2025:
Species
The family contains 27 recent species in 5 genera, as well as a number of fossil species and genera.
The following classification is based on ''
Eschmeyer's Catalog of Fishes
Catalog of Fishes is a comprehensive on-line database and reference work on the scientific names of fish species and genera. It is global in its scope and is hosted by the California Academy of Sciences. It has been compiled and is continuously up ...
'' (2025):

Family
Acipenseridae
Sturgeon (from Old English ultimately from Proto-Indo-European language, Proto-Indo-European *''str̥(Hx)yón''-) is the common name for the 27 species of fish belonging to the family Acipenseridae. The earliest sturgeon fossils date to the ...
* Genus ''
Acipenser
''Acipenser'' is a genus of sturgeons, containing three species native to freshwater and estuarine systems of eastern North America and Europe. It is the type genus of the family Acipenseridae and the order Acipenseriformes.
Taxonomy
Prior t ...
''
Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
, 1758 (native to eastern
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
and western Europe)
** ''
Acipenser desotoi''
Vladykov, 1955 (
Gulf sturgeon)
** ''
Acipenser oxyrinchus
The Atlantic sturgeon (''Acipenser oxyrinchus'') is a large species of sturgeon native to both sides of the Atlantic Ocean, and associated river basins. It is a member of the family Acipenseridae, and, along with other sturgeon, it is sometime ...
''
Mitchill, 1815 (
Atlantic sturgeon
The Atlantic sturgeon (''Acipenser oxyrinchus'') is a large species of sturgeon native to both sides of the Atlantic Ocean, and associated river basins. It is a member of the family Acipenseridae, and, along with other sturgeon, it is sometimes ...
)
** ''
Acipenser sturio''
Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
, 1758
Events
January–March
* January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoologic ...
(
European sea sturgeon)
* Genus ''
Scaphirhynchus
''Scaphirhynchus'' is a genus of sturgeons native to North America. All species in this genus are considered to be Threatened species, threatened with extinction or worse. As of 2023, the pallid sturgeon (''S. albus'') and the Alabama sturgeon ( ...
''
Heckel, 1835 (native to central North America)
** ''
Scaphirhynchus albus
The pallid sturgeon (''Scaphirhynchus albus'') is an endangered species of Actinopterygii, ray-finned fish, endemic to the waters of the Missouri River, Missouri and lower Mississippi River basins of the United States. It may have even reached ...
''
(Forbes
''Forbes'' () is an American business magazine founded by B. C. Forbes in 1917. It has been owned by the Hong Kong–based investment group Integrated Whale Media Investments since 2014. Its chairman and editor-in-chief is Steve Forbes. The co ...
& R. E. Richardson, 1905) (
pallid sturgeon
The pallid sturgeon (''Scaphirhynchus albus'') is an endangered species of ray-finned fish, endemic to the waters of the Missouri and lower Mississippi River basins of the United States. It may have even reached the St. Croix River before colo ...
)
** ''
Scaphirhynchus platorynchus
The shovelnose sturgeon (''Scaphirhynchus platorynchus'') is the smallest species of freshwater sturgeon native to North America. It is often called hackleback, sand sturgeon, or switchtail. Switchtail refers to the long filament found on the up ...
''
(Rafinesque
Constantine Samuel Rafinesque-Schmaltz (; 22 October 178318 September 1840) was a French early 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ult ...
, 1820) (
shovelnose sturgeon)
** ''
Scaphirhynchus suttkusi
The Alabama sturgeon (''Scaphirhynchus suttkusi'') is a species of sturgeon native to the United States of America and now only believed to exist in of the lower Alabama River. Its historical ranges were believed to be over 1600 rkm and incl ...
''
J. D. Williams & Clemmer, 1991 (
Alabama sturgeon
The Alabama sturgeon (''Scaphirhynchus suttkusi'') is a species of sturgeon native to the United States of America and now only believed to exist in of the lower Alabama River. Its historical ranges were believed to be over 1600 rkm and incl ...
)
*Genus ''
Sinosturio''
Jaekel ''in'' Weigelt, 1929 (native to
East Asia
East Asia is a geocultural region of Asia. It includes China, Japan, Mongolia, North Korea, South Korea, and Taiwan, plus two special administrative regions of China, Hong Kong and Macau. The economies of Economy of China, China, Economy of Ja ...
and western North America)
**
''Sinosturio'' ''dabryanus'' ( A. H. A. Duméril, 1869) (
Yangtze sturgeon)
**''
Sinosturio dauricus''
( Georgi, 1775) (
kaluga
Kaluga (, ) is a types of inhabited localities in Russia, city and the administrative center of Kaluga Oblast, Russia. It stands on the Oka River southwest of Moscow. Its population was 337,058 at the 2021 census.
Kaluga's most famous residen ...
)
** ''
Sinosturio medirostris''
( Ayres, 1854) (
green sturgeon)
** ''
Sinosturio mikadoi''
( Hilgendorf, 1892) (
Sakhalin sturgeon)
** ''
Sinosturio schrenckii''
( J. F. Brandt, 1869) (
Amur sturgeon)
** ''
Sinosturio sinensis''
( J. E. Gray, 1835) (
Chinese sturgeon)
** ''
Sinosturio transmontanus''
( J. Richardson, 1836) (
white sturgeon)
* Genus ''
Huso
''Huso'' is a genus of sturgeons from eastern Europe, Asia, and eastern North America. The genus name is derived from ''wikt:huso, hūso'', the Old High German and Medieval Latin word for "sturgeon", which is also ancestral to ''wikt:Hausen, Haus ...
''
J. F. Brandt & Ratzeburg
Ratzeburg (; Low German: ''Ratzborg'') is a town in Schleswig-Holstein, Germany. It is surrounded by Ratzeburger See, four lakes—the resulting isthmuses between the lakes form the access lanes to the town. Ratzeburg is the capital of the distri ...
, 1833 (native to eastern Europe,
west Asia
West Asia (also called Western Asia or Southwest Asia) is the westernmost region of Asia. As defined by most academics, UN bodies and other institutions, the subregion consists of Anatolia, the Arabian Peninsula, Iran, Mesopotamia, the Armenian ...
, and eastern North America)
** ''
Huso baerii''
( J. F. Brandt, 1869) (
Siberian sturgeon)
*** ''
Huso baerii baicalensis''
( A. M. Nikolskii, 1896) (
Baikal sturgeon)
*** ''
Huso
''Huso'' is a genus of sturgeons from eastern Europe, Asia, and eastern North America. The genus name is derived from ''wikt:huso, hūso'', the Old High German and Medieval Latin word for "sturgeon", which is also ancestral to ''wikt:Hausen, Haus ...
'' ''
baerii stenorrhynchus''
( A. M. Nikolskii, 1896)
** ''
Huso brevirostrum''
( Lesueur, 1818) (
shortnose sturgeon
The shortnose sturgeon (''Huso brevirostrum'') is a small and endangered species of North American sturgeon. As with most sturgeons, it is an anadromous bottom-feeder, which migrates upstream to spawn but spends most of its life feeding in rive ...
)
** ''
Huso colchicus''
(Marty, 1940) (
Caucasian sturgeon)
** ''
Huso fulvescens''
(Rafinesque
Constantine Samuel Rafinesque-Schmaltz (; 22 October 178318 September 1840) was a French early 19th-century polymath born near Constantinople in the Ottoman Empire and self-educated in France. He traveled as a young man in the United States, ult ...
, 1817) (
lake sturgeon
The lake sturgeon (''Huso fulvescens''), also known as the rock sturgeon, is a North American temperate freshwater fish, one of 27 species of sturgeon. Like other sturgeons, this species is a bottom feeder and has a partly cartilaginous skele ...
)
** ''
Huso gueldenstaedtii''
( J. F. Brandt & Ratzeburg
Ratzeburg (; Low German: ''Ratzborg'') is a town in Schleswig-Holstein, Germany. It is surrounded by Ratzeburger See, four lakes—the resulting isthmuses between the lakes form the access lanes to the town. Ratzeburg is the capital of the distri ...
, 1833) (
Russian sturgeon
The Russian sturgeon (''Huso gueldenstaedtii''), also known as the diamond sturgeon or Danube sturgeon, is a species of fish in the family Acipenseridae. It is found in Azerbaijan, Bulgaria, Georgia, Iran, Kazakhstan, Romania, Russia, Turkey, Tur ...
)
** ''
Huso huso''
(Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
, 1758
Events
January–March
* January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoologic ...
) (
beluga
Beluga may refer to:
Animals
*Beluga (sturgeon)
* Beluga whale
Vehicles
* Airbus Beluga, a large transport airplane
* Airbus BelugaXL, a larger transport airplane
* Beluga-class submarine, a class of Russian SSA diesel-electric submarine
* U ...
)
** ''
Huso naccarii''
( Bonaparte, 1836) (
Adriatic sturgeon)
** ''
Huso nudiventris''
( Lovetsky, 1828) (
fringebarbel sturgeon)
** ''
Huso persicus''
( Borodin, 1897) (
Persian sturgeon)
** ''
Huso ruthenus''
(Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
, 1758
Events
January–March
* January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of ''Systema Naturae'', the starting point of modern zoologic ...
) (
sterlet
The sterlet (''Huso ruthenus'') is a relatively small species of sturgeon from Eurasia native to large rivers that flow into the Black Sea, Azov Sea, and Caspian Sea, as well as rivers in Siberia as far east as Yenisei River, Yenisei. Population ...
)
** ''
Huso stellatus''
(Pallas
Pallas may refer to:
Astronomy
* 2 Pallas asteroid
** Pallas family, a group of asteroids that includes 2 Pallas
* Pallas (crater), a crater on Earth's moon
Mythology
* Pallas (Giant), a son of Uranus and Gaia, killed and flayed by Athena
* Pa ...
, 1771) (
starry sturgeon)
* Genus ''
Pseudoscaphirhynchus
''Pseudoscaphirhynchus'' is a genus of relatively small, highly threatened sturgeons that are restricted to the Aral Sea system (although Local extinction, extirpated from the Aral Sea itself), including the Amu Darya and Syr Darya river basins, ...
''
Nikolskii, 1900 (native to
Central Asia
Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...
)
** ''
Pseudoscaphirhynchus fedtschenkoi
The Syr Darya sturgeon (''Pseudoscaphirhynchus fedtschenkoi''), or Syr Darya shovelnose sturgeon, is a species of fish in the family Acipenseridae. It is found in Kazakhstan, Tajikistan and Uzbekistan, where it is Endemism, endemic to the Syr Da ...
''
( Kessler, 1872) (
Syr Darya sturgeon)
** ''
Pseudoscaphirhynchus hermanni''
( Kessler, 1877) (
dwarf sturgeon)
** ''
Pseudoscaphirhynchus kaufmanni
The Amu Darya sturgeon or false shovelnose sturgeon (''Pseudoscaphirhynchus kaufmanni'') is a critically endangered species of fish in the family (biology), family Acipenseridae. It is found in Turkmenistan, Uzbekistan, Tajikistan and perhaps Af ...
''
( Kessler, 1877) (
Amu Darya sturgeon)
File:Young lake sturgeon.jpg, A young lake sturgeon (''Huso fulvescens'')
File:Hausen (Huso huso L.)editDOB.JPG, Great sturgeon or beluga (''Huso huso'') feeding on another fish
File:Pallid sturgeon activity with syphoning.webmhd.webm, Pallid sturgeon (''Scaphirhynchus albus'') showing siphoning feeding behaviour
File:Beluga sturgeon in aquarium.webm, Beluga sturgeon in an aquarium.
Fossil taxa

Fossil sturgeons are known from the mid-late
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
onwards. The earliest known sturgeon fossil is of an indeterminate partial skull from the
Cenomanian
The Cenomanian is, in the International Commission on Stratigraphy's (ICS) geological timescale, the oldest or earliest age (geology), age of the Late Cretaceous epoch (geology), Epoch or the lowest stage (stratigraphy), stage of the Upper Cretace ...
-aged
Dunvegan Formation of Alberta, Canada.
It was previously assumed that from ''
Asiacipenser kotelnikovi''
Nessov, 1990 from the
Late Jurassic
The Late Jurassic is the third Epoch (geology), epoch of the Jurassic Period, and it spans the geologic time scale, geologic time from 161.5 ± 1.0 to 143.1 ± 0.8 million years ago (Ma), which is preserved in Upper Jurassic stratum, strata.Owen ...
of Kazakhstan was the earliest sturgeon, but these remains are non-diagnostic and it is unlikely that it represents a member of the family.
They become particularly diverse during the
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...
of North America, where multiple different genera are known.
The following species are known:
* Genus "''
Acipenser
''Acipenser'' is a genus of sturgeons, containing three species native to freshwater and estuarine systems of eastern North America and Europe. It is the type genus of the family Acipenseridae and the order Acipenseriformes.
Taxonomy
Prior t ...
"''
Linnaeus
Carl Linnaeus (23 May 1707 – 10 January 1778), also known after ennoblement in 1761 as Carl von Linné,#Blunt, Blunt (2004), p. 171. was a Swedish biologist and physician who formalised binomial nomenclature, the modern system of naming o ...
, 1758 (''Acipenser
sensu lato
''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...
'')
** †''
"Acipenser" albertensis''
Lambe, 1902 (
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''cre ...
of Alberta, Canada)
** †''
"''
''Acipenser"'' ''anisinferos'' Hilton & Grande, 2023 (Late Cretaceous of North Dakota, USA)
** †''
"Acipenser" chilini''
Nessov, 1983 (
Early Paleocene
The Danian is the oldest age (geology), age or lowest stage (stratigraphy), stage of the Paleocene Epoch or series (stratigraphy), Series, of the Paleogene Period or system (stratigraphy), System, and of the Cenozoic Era or Erathem. The beginnin ...
of Kazakhstan)
** ?†''
"Acipenser" cretaceous''
Daimeries, 1892 (Late Cretaceous of Belgium; potentially a
teleost
Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all neontology, extant species of f ...
)
** †''
"Acipenser" eruciferus''
Cope
A cope ( ("rain coat") or ("cape")) is a liturgical long mantle or cloak, open at the front and fastened at the breast with a band or clasp. It may be of any liturgical colour.
A cope may be worn by any rank of the Catholic or Anglican clerg ...
, 1876 (Late Cretaceous of Montana, USA)
** †''
"Acipenser" gigantissimus''
Nessov, 1997 (Late Cretaceous of Saratov, Russia)
** †''
"Acipenser" lemoinei''
(Priem, 1901) (
Early Eocene
In the geologic timescale the Ypresian is the oldest age (geology), age or lowest stage (stratigraphy), stratigraphic stage of the Eocene. It spans the time between , is preceded by the Thanetian Age (part of the Paleocene) and is followed by th ...
of France)
** ?†''
"Acipenser" molassicus''
Probst, 1882 (
Miocene
The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...
of Germany; potentially a
chondrichthyan)
** †''
"Acipenser" ornatus''
Leidy, 1873 (Miocene of Virginia, USA)
** †''
"Acipenser" parisiensis''
Priem, 1908 (
Early Oligocene
The Rupelian is, in the geologic timescale, the older of two age (geology), ages or the lower of two stage (stratigraphy), stages of the Oligocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between . It is preceded b ...
of France)
** †''
"Acipenser" praeparatorum''
Hilton & Grande, 2023 (Late Cretaceous of North Dakota, USA)
** †''
"Acipenser" toliapicus''
Agassiz
Jean Louis Rodolphe Agassiz ( ; ) FRS (For) FRSE (May 28, 1807 – December 14, 1873) was a Swiss-born American biologist and geologist who is recognized as a scholar of Earth's natural history.
Spending his early life in Switzerland, he recei ...
1844 ''ex'' Woodward 1889 (Early Eocene of England)
** ?†''
"Acipenser" tuberculosus''
Probst 1882 (Miocene of Germany; potentially a chondrichthyan)
** †''
"Acipenser" zhylgensis''
Nessov, 1983 (Early Paleocene of Kazakhstan)
*Genus †''
Anchiacipenser''
Sato, Murray, Vernygora & Currie, 2018
**†''Anchiacipenser'' ''acanthaspis''
Sato, Murray, Vernygora & Currie, 2018 (Late Cretaceous of Alberta, Canada & Montana, USA)
*Genus †''
Boreiosturion''
Murray, Nelson & Brinkman, 2023
**†''Boreiosturion labyrinthicus''
Murray, Nelson & Brinkman, 2023 (Late Cretaceous of Alberta, Canada)
*Genus †''
Engdahlichthys''
Murray, Brinkman, DeMar & Wilson, 2020
**†''Engdahlichthys milviaegis''
Murray, Brinkman, DeMar & Wilson, 2020 (
Early Paleocene
The Danian is the oldest age (geology), age or lowest stage (stratigraphy), stage of the Paleocene Epoch or series (stratigraphy), Series, of the Paleogene Period or system (stratigraphy), System, and of the Cenozoic Era or Erathem. The beginnin ...
of Montana, USA)
*Genus †''
Protoscaphirhynchus''
Wilimovsky, 1956
**†''Protoscaphirhynchus squamosus''
Wilimovsky, 1956 (Late Cretaceous of Montana, USA)
*Subfamily †
Priscosturioninae Grande & Hilton, 2009
**Genus †''
Priscosturion''
Grande & Hilton, 2009 (=''Psammorhynchus''
Grande & Hilton, 2006)
***†''Priscosturion longipinnis''
(Grande & Hilton, 2006) (Late Cretaceous of Alberta, Canada)
Most fossil species placed in "''Acipenser''" are thought to be ''
nomina dubia'', being based on fragmentary remains that do not display diagnostic traits.
The exceptions are ''"A.''" ''praeparatorum'' and ''"A.''" ''anisinferos'' from the
Hell Creek Formation
The Hell Creek Formation is an intensively studied division of mostly Upper Cretaceous and some lower Paleocene rocks in North America, named for exposures studied along Hell Creek, near Jordan, Montana. The Formation (stratigraphy), formation s ...
, which are known from well-preserved remains.
''A. praeparotorum'' may potentially represent a basal member of the ''Huso''-''Pseudoscaphirhynchus'' lineage.
Range and habitat
Sturgeon range from
subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones immediately to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Ge ...
to
subarctic
The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of hemiboreal regions and covering much of Alaska, Canada, Iceland, the north of Fennoscandia, Northwestern Russia, Siberia, and the Cair ...
waters in
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
and
Eurasia
Eurasia ( , ) is a continental area on Earth, comprising all of Europe and Asia. According to some geographers, Physical geography, physiographically, Eurasia is a single supercontinent. The concept of Europe and Asia as distinct continents d ...
. In
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
, they range along the Atlantic Coast from the
Gulf of Mexico
The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...
to
Newfoundland
Newfoundland and Labrador is the easternmost province of Canada, in the country's Atlantic region. The province comprises the island of Newfoundland and the continental region of Labrador, having a total size of . As of 2025 the population ...
, including the
Great Lakes
The Great Lakes, also called the Great Lakes of North America, are a series of large interconnected freshwater lakes spanning the Canada–United States border. The five lakes are Lake Superior, Superior, Lake Michigan, Michigan, Lake Huron, H ...
and the
St. Lawrence,
Missouri
Missouri (''see #Etymology and pronunciation, pronunciation'') is a U.S. state, state in the Midwestern United States, Midwestern region of the United States. Ranking List of U.S. states and territories by area, 21st in land area, it border ...
, and
Mississippi
Mississippi ( ) is a U.S. state, state in the Southeastern United States, Southeastern and Deep South regions of the United States. It borders Tennessee to the north, Alabama to the east, the Gulf of Mexico to the south, Louisiana to the s ...
Rivers, as well as along the West Coast in major rivers from
California
California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...
and
Idaho
Idaho ( ) is a landlocked U.S. state, state in the Pacific Northwest and Mountain states, Mountain West subregions of the Western United States. It borders Montana and Wyoming to the east, Nevada and Utah to the south, and Washington (state), ...
to
British Columbia
British Columbia is the westernmost Provinces and territories of Canada, province of Canada. Situated in the Pacific Northwest between the Pacific Ocean and the Rocky Mountains, the province has a diverse geography, with rugged landscapes that ...
. They occur along the European
Atlantic
The Atlantic Ocean is the second largest of the world's five oceanic divisions, with an area of about . It covers approximately 17% of Earth's surface and about 24% of its water surface area. During the Age of Discovery, it was known for se ...
coast, including the
Mediterranean
The Mediterranean Sea ( ) is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean basin and almost completely enclosed by land: on the east by the Levant in West Asia, on the north by Anatolia in West Asia and Southern ...
basin, especially in the
Adriatic Sea
The Adriatic Sea () is a body of water separating the Italian Peninsula from the Balkans, Balkan Peninsula. The Adriatic is the northernmost arm of the Mediterranean Sea, extending from the Strait of Otranto (where it connects to the Ionian Se ...
and the rivers of
North Italy
Northern Italy (, , ) is a geographical and cultural region in the northern part of Italy. The Italian National Institute of Statistics defines the region as encompassing the four northwestern regions of Piedmont, Aosta Valley, Liguria and Lomb ...
; in the rivers that flow into the
Black
Black is a color that results from the absence or complete absorption of visible light. It is an achromatic color, without chroma, like white and grey. It is often used symbolically or figuratively to represent darkness.Eva Heller, ''P ...
,
Azov
Azov (, ), previously known as Azak ( Turki/ Kypchak: ),
is a town in Rostov Oblast, Russia, situated on the Don River just from the Sea of Azov, which derives its name from the town. The population is
History
Early settlements in the vici ...
, and
Caspian Seas (
Danube
The Danube ( ; see also #Names and etymology, other names) is the List of rivers of Europe#Longest rivers, second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest sou ...
,
Dnepr,
Volga
The Volga (, ) is the longest river in Europe and the longest endorheic basin river in the world. Situated in Russia, it flows through Central Russia to Southern Russia and into the Caspian Sea. The Volga has a length of , and a catchment ...
,
Ural and
Don); the north-flowing rivers of Russia that feed the
Arctic Ocean
The Arctic Ocean is the smallest and shallowest of the world's five oceanic divisions. It spans an area of approximately and is the coldest of the world's oceans. The International Hydrographic Organization (IHO) recognizes it as an ocean, ...
(
Ob,
Yenisei,
Lena,
Kolyma
Kolyma (, ) or Kolyma Krai () is a historical region in the Russian Far East that includes the basin of Kolyma River and the northern shores of the Sea of Okhotsk, as well as the Kolyma Mountains (the watershed of the two). It is bounded to ...
); in the rivers of
Central Asia
Central Asia is a region of Asia consisting of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan. The countries as a group are also colloquially referred to as the "-stans" as all have names ending with the Persian language, Pers ...
(
Amu Darya
The Amu Darya ( ),() also shortened to Amu and historically known as the Oxus ( ), is a major river in Central Asia, which flows through Tajikistan, Turkmenistan, Uzbekistan, and Afghanistan. Rising in the Pamir Mountains, north of the Hindu Ku ...
and
Syr Darya
The Syr Darya ( ),; ; ; ; ; /. historically known as the Jaxartes ( , ), is a river in Central Asia. The name, which is Persian language, Persian, literally means ''Syr Sea'' or ''Syr River''. It originates in the Tian Shan, Tian Shan Mountain ...
) and
Lake Baikal
Lake Baikal is a rift lake and the deepest lake in the world. It is situated in southern Siberia, Russia between the Federal subjects of Russia, federal subjects of Irkutsk Oblast, Irkutsk Oblasts of Russia, Oblast to the northwest and the Repu ...
. In the Pacific Ocean, they are found in the
Amur River
The Amur River () or Heilong River ( zh, s=黑龙江) is a perennial river in Northeast Asia, forming the natural border between the Russian Far East and Northeast China (historically the Outer and Inner Manchuria). The Amur ''proper'' is ...
along the Russian-
Chinese border, on
Sakhalin
Sakhalin ( rus, Сахали́н, p=səxɐˈlʲin) is an island in Northeast Asia. Its north coast lies off the southeastern coast of Khabarovsk Krai in Russia, while its southern tip lies north of the Japanese island of Hokkaido. An islan ...
Island, and some 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
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
, overfishing, and pollution.
No species is known to naturally occur south of the equator, though attempts at sturgeon
aquaculture
Aquaculture (less commonly spelled aquiculture), also known as aquafarming, is the controlled cultivation ("farming") of aquatic organisms such as fish, crustaceans, mollusks, algae and other organisms of value such as aquatic plants (e.g. Nelu ...
are being made in
Uruguay
Uruguay, officially the Oriental Republic of Uruguay, is a country in South America. It shares borders with Argentina to its west and southwest and Brazil to its north and northeast, while bordering the Río de la Plata to the south and the A ...
,
South Africa
South Africa, officially the Republic of South Africa (RSA), is the Southern Africa, southernmost country in Africa. Its Provinces of South Africa, nine provinces are bounded to the south by of coastline that stretches along the Atlantic O ...
, and other places.
Most species are at least partially
anadromous
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousa ...
,
spawning
Spawn is the Egg cell, eggs and Spermatozoa, sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of freely releasing eggs and sperm into a body of water (fresh or marine); the physical act is ...
in fresh water and feeding in nutrient-rich, brackish waters of
estuaries
An estuary is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environm ...
or undergoing significant migrations along coastlines. However, some species have evolved purely freshwater existences, such as the
lake sturgeon
The lake sturgeon (''Huso fulvescens''), also known as the rock sturgeon, is a North American temperate freshwater fish, one of 27 species of sturgeon. Like other sturgeons, this species is a bottom feeder and has a partly cartilaginous skele ...
(''Acipenser fulvescens'') and the
Baikal sturgeon (''A. baerii baicalensis''), or have been forced into them by human or natural
impoundment of their native rivers, as in the case of some subpopulations of
white sturgeon (''A. transmontanus'') in the
Columbia River
The Columbia River (Upper Chinook language, Upper Chinook: ' or '; Sahaptin language, Sahaptin: ''Nch’i-Wàna'' or ''Nchi wana''; Sinixt dialect'' '') is the largest river in the Pacific Northwest region of North America. The river headwater ...
and
Siberian sturgeon (''A. baerii'') in the Ob basin.
Physical characteristics

Sturgeons retain several primitive characteristics from the bony fishes. Along with other members of the
subclass Chondrostei
Chondrostei is a subclass of non- neopterygian ray-finned fish. While the term originally referred to the paraphyletic grouping of all non-neopterygian ray-finned fish, it was redefined by Patterson in 1982 to be a clade comprising the Acipenser ...
, they are unique among bony fishes because their skeletons are almost entirely
cartilaginous
Cartilage is a resilient and smooth type of connective tissue. Semi-transparent and non-porous, it is usually covered by a tough and fibrous membrane called perichondrium. In tetrapods, it covers and protects the ends of long bones at the joints ...
. To maintain structure, sturgeons are one of few organisms to retain a post-embryonic
notochord
The notochord is an elastic, rod-like structure found in chordates. In vertebrates the notochord is an embryonic structure that disintegrates, as the vertebrae develop, to become the nucleus pulposus in the intervertebral discs of the verteb ...
that acts like a soft spine running through the body. Notably, however, the cartilaginous skeleton is not a primitive character, but a derived one; sturgeon ancestors had bony skeletons.
They also lack
vertebral centra, and are partially covered with five lateral rows of scutes rather than
scales
Scale or scales may refer to:
Mathematics
* Scale (descriptive set theory), an object defined on a set of points
* Scale (ratio), the ratio of a linear dimension of a model to the corresponding dimension of the original
* Scale factor, a number ...
.
They also have four
barbels
In fish anatomy and turtle anatomy, a barbel is a slender, whisker like sensory organ near the mouth (sometimes called whiskers or tendrils). Fish that have barbels include the catfish, the carp, the goatfish, the hagfish, the sturgeon, the z ...
—sensory organs that precede their wide, toothless mouths. They navigate their riverine habitats traveling just off the bottom with their barbels dragging along gravel, or murky substrate. Sturgeon are recognizable for their elongated bodies, flattened
rostra
The Rostra () was a large platform built in the city of Rome that stood during the republican and imperial periods. Speakers would stand on the rostra and face the north side of the Comitium towards the senate house and deliver orations to t ...
, distinctive scutes and barbels, and elongated upper tail lobes. The skeletal support for the paired fins of ray-finned fish is inside the body wall, although the ray-like structures in the webbing of the fins can be seen externally.
Sturgeons are among the largest fish: some
beluga
Beluga may refer to:
Animals
*Beluga (sturgeon)
* Beluga whale
Vehicles
* Airbus Beluga, a large transport airplane
* Airbus BelugaXL, a larger transport airplane
* Beluga-class submarine, a class of Russian SSA diesel-electric submarine
* U ...
(''Huso huso'') in the
Caspian Sea
The Caspian Sea is the world's largest inland body of water, described as the List of lakes by area, world's largest lake and usually referred to as a full-fledged sea. An endorheic basin, it lies between Europe and Asia: east of the Caucasus, ...
reportedly attain over and while for
kaluga
Kaluga (, ) is a types of inhabited localities in Russia, city and the administrative center of Kaluga Oblast, Russia. It stands on the Oka River southwest of Moscow. Its population was 337,058 at the 2021 census.
Kaluga's most famous residen ...
(''H. dauricus'') in the
Amur River
The Amur River () or Heilong River ( zh, s=黑龙江) is a perennial river in Northeast Asia, forming the natural border between the Russian Far East and Northeast China (historically the Outer and Inner Manchuria). The Amur ''proper'' is ...
, similar lengths and over weights have been reported. They are also among the longest-lived of the fishes, some living well over 100 years and attaining sexual maturity at 20 years or more.
[Berg, L.S. (1962). Freshwater fishes of the U.S.S.R. and adjacent countries. volume 1, 4th edition. Israel Program for Scientific Translations Ltd., Jerusalem. (Russian version published 1948).] 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 is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing Fish stocks, fish stock), resu ...
.
Sturgeons are
polyploid
Polyploidy is a condition in which the biological cell, cells of an organism have more than two paired sets of (Homologous chromosome, homologous) chromosomes. Most species whose cells have Cell nucleus, nuclei (eukaryotes) are diploid, meaning ...
; some species have four, eight, or 16 sets of chromosomes.
Life cycle
Sturgeons are long-lived, late maturing fishes. Their average lifespan is 50 to 60 years, and their first
spawn does not occur until they are around 15 to 20 years old. Sturgeons are broadcast spawners, and do not spawn every year because they require specific conditions. Those requirements may or may not be met every year due to varying environmental conditions, such as the proper
photoperiod in spring, clear water with shallow rock or gravel
substrate
Substrate may refer to:
Physical layers
*Substrate (biology), the natural environment in which an organism lives, or the surface or medium on which an organism grows or is attached
** Substrate (aquatic environment), the earthy material that exi ...
, where the eggs can adhere, and proper water temperature and flow for
oxygenation of the eggs. A single female may release 100,000 to 3 million eggs, but not all will be fertilized. The fertilized eggs become sticky and adhere to the bottom substrate upon contact. Eight to 15 days are needed for the embryos to mature into
larval fish. During that time, they are dependent on their yolk sacs for nourishment.
River currents carry the larvae downstream into backwater areas, such as
oxbows and
sloughs, where the free-swimming
fry spend their first year feeding on insect larvae and
crustacea
Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...
. During their first year of growth, they reach in length and migrate back into the swift-flowing currents in the
main stem river.
Behavior

Sturgeons are primarily
benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from the Ancient Greek word (), meaning "the depths". ...
feeders, with a diet of shellfish, crustaceans, and small fish. Exceptionally, both ''Huso'' species, the
white sturgeon and the
pallid sturgeon
The pallid sturgeon (''Scaphirhynchus albus'') is an endangered species of ray-finned fish, endemic to the waters of the Missouri and lower Mississippi River basins of the United States. It may have even reached the St. Croix River before colo ...
feed primarily on other fish as adults. They feed by extending their siphon-like mouths to suck food from the
benthos
Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.[salmon
Salmon (; : salmon) are any of several list of commercially important fish species, commercially important species of euryhaline ray-finned fish from the genera ''Salmo'' and ''Oncorhynchus'' of the family (biology), family Salmonidae, native ...](_bl ...<br></span></div>. Having no teeth, they are unable to seize prey, though larger individuals and more predatory species can swallow very large prey items, including whole <div class=)
. Sturgeons feed non-visually. They are believed to use a combination of sensors, including olfactory, tactile, and chemosensory cues detected by the four barbels, and
electroreception
Electroreception and electrogenesis are the closely related biological abilities to perceive electrical stimuli and to generate electric fields. Both are used to locate prey; stronger electric discharges are used in a few groups of fishes, such ...
using their
ampullae of Lorenzini
Ampullae of Lorenzini (: ''ampulla'') are electroreceptors, sense organs able to detect electric fields. They form a network of mucus-filled pores in the skin of Chondrichthyes, cartilaginous fish (sharks, Ray (fish), rays, and chimaeras) and of ...
.
The sturgeons' electroreceptors are located on the head and are sensitive to weak electric fields generated by other animals or geoelectric sources.
The electroreceptors are thought to be used in various behaviors such as feeding, mating and migration.
Many sturgeons leap completely out of the water,
usually making a loud splash which can be heard half a mile away on the surface and probably farther under water. Why they do this is not known, but suggested functions include group communication to maintain group cohesion, catching airborne prey,
courtship display
A courtship display is a set of display behaviors in which an animal, usually a male, attempts to attract a mate; the mate exercises choice, so sexual selection acts on the display. These behaviors often include ritualized movement ("dances"), ...
, or to help shed eggs during spawning. Other plausible explanations include escape from predators, shedding parasites, or to gulp or expel air.
Another explanation is that it "simply feels good".
There have been some incidents of leaping sturgeon landing in boats and causing injuries to humans;
in 2015, a 5-year-old girl was fatally injured after a sturgeon leapt from the
Suwannee River
The Suwannee River (also spelled Suwanee River or Swanee River) is a river that runs through south Georgia southward into Florida in the Southern United States. It is a wild blackwater river, about long.U.S. Geological Survey. National Hydrog ...
and struck her.
Interactions with humans
Caviar

Globally, sturgeon fisheries are of great value, primarily as a source for
caviar
Caviar or caviare is a food consisting of salt-cured roe of the family Acipenseridae. Caviar is considered a delicacy and is eaten as a garnish or spread. Traditionally, the term caviar refers only to roe from wild sturgeon in the Caspi ...
, but also for flesh.
Several species of sturgeon are harvested for their roe which is processed into caviar—a
delicacy
A delicacy is a rare food item that is considered highly desirable, sophisticated, or peculiarly distinctive within a given culture or region. A delicacy may have an unusual flavor or be expensive compared to everyday foods.
Delicacies va ...
, and the reason why caviar-producing sturgeons are among the most valuable and endangered of all wildlife resources.
During the 19th century, the US was the global leader in caviar production, having cornered 90% of the world's caviar trade.
Atlantic sturgeon once thrived along the east coast from Canada down to
Florida
Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...
. They were in such abundance in the
Hudson River
The Hudson River, historically the North River, is a river that flows from north to south largely through eastern New York (state), New York state. It originates in the Adirondack Mountains at Henderson Lake (New York), Henderson Lake in the ...
that they were
humorously called "Albany beef" and sturgeon eggs were given away at local bars as an accompaniment to 5¢ beer.
White sturgeon populations along the US west coast declined simultaneously under the pressure of commercial fishing and human encroachment. Within the course of a century, the once abundant sturgeon fisheries in the US and Canada had drastically declined, and in some areas had been extirpated under the pressure of commercial overharvesting, pollution, human encroachment, habitat loss, and the damming of rivers that blocked their ancestral migration to spawning grounds.
By the turn of the century, commercial production of sturgeon caviar in the US and Canada had come to an end. Regulatory protections and conservation efforts were put in place by state and federal resource agencies in the US and Canada, such as the 1998 US federal moratorium that closed all commercial fishing for Atlantic sturgeon.[ It was during the 20th century that Russia grew to become the global leader as the largest producer and exporter of caviar.][ As with the decline in sturgeon populations in the US and Canada, the same occurred with sturgeon populations in the Caspian Sea.]
Beginning with the 1979 US embargo on Iran, poaching
Poaching is the illegal hunting or capturing of wild animals, usually associated with land use rights.
Poaching was once performed by impoverished peasants for subsistence purposes and to supplement meager diets. It was set against the huntin ...
and smuggling sturgeon caviar was big business but an illegal and dangerous one. Officers with the Washington Department of Fish and Wildlife (WDFW) busted a poaching ring that was based in Vancouver, Washington
Vancouver ( ) is a city on the north bank of the Columbia River in the U.S. state of Washington (state), Washington, located in Clark County, Washington, Clark County. Founded in 1825 and incorporated in 1857, Vancouver had a population of 190, ...
. The poachers had harvested 1.65 tons of caviar from nearly 2,000 white sturgeon that were poached from the Columbia River. The caviar was estimated to be worth around $2 million. WDFW busted another ring in 2003, and conducted an undercover sting operation in 2006–2007 that resulted in 17 successful attempts out of a total of 19.
In response to concerns over the future of sturgeons and associated commercial products, international trade for all species of sturgeons has been regulated under CITES
CITES (shorter acronym for the Convention on International Trade in Endangered Species of Wild Fauna and Flora, also known as the Washington Convention) is a multilateral treaty to protect endangered plants and animals from the threats of inte ...
since 1998.
Conservation
Sturgeons are threatened by the negative impacts of overfishing, poaching, habitat destruction
Habitat destruction (also termed habitat loss or habitat reduction) occurs when a natural habitat is no longer able to support its native species. The organisms once living there have either moved elsewhere, or are dead, leading to a decrease ...
, and the construction of dams that have altered or blocked their annual migration to ancestral spawning grounds. Some species of sturgeon are extinct, and several are on the verge of extinction, including the Chinese sturgeon, the highly prized beluga sturgeon, and the Alabama sturgeon
The Alabama sturgeon (''Scaphirhynchus suttkusi'') is a species of sturgeon native to the United States of America and now only believed to exist in of the lower Alabama River. Its historical ranges were believed to be over 1600 rkm and incl ...
. Many species are classified as threatened or endangered, with noticeable declines in sturgeon populations as the demand for caviar increases. IUCN
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status ...
data indicates that over 85% of sturgeon species are at risk of extinction, making them more critically endangered than any other group of animal species.
In addition to global restocking efforts, the monitoring of populations and habitat, and various other conservation efforts by national and state resource agencies as applicable to their respective countries, several conservation organizations have been formed to assist in the preservation of sturgeons around the world. On a global scale, one such organization is the World Sturgeon Conservation Society (WSCS) whose primary objectives include fostering the "conservation of sturgeon species and restoration of sturgeon stocks world-wide", and supporting the "information exchange among all persons interested in sturgeons." The North American Sturgeon and Paddlefish Society (NASPS) and Gesellschaft zur Rettung des Störs e.V. are WSCS affiliates. WSCS has been instrumental in organizing global conferences where scientists and researchers can exchange information and address the various conservation challenges that threaten the future of sturgeons. Conservation efforts at the grass roots level are also instrumental in helping to preserve sturgeon populations, such as Sturgeon For Tomorrow which was founded in 1977, consists of volunteers and a sturgeon guarding program to monitor known spawning sites. The organization has grown exponentially over the years and has become "the largest citizen advocacy group for sturgeon in the world", and has expanded with affiliate chapters in other states that have sturgeon populations. Other projects focus on specific local issues, such as the We Pass project, seeking a solution to the migratory impasse represented by the Iron Gates in the Danube River Basin. For example, currently all anadromous Danube
The Danube ( ; see also #Names and etymology, other names) is the List of rivers of Europe#Longest rivers, second-longest river in Europe, after the Volga in Russia. It flows through Central and Southeastern Europe, from the Black Forest sou ...
sturgeon (all species except the predominantly freshwater sterlet) are now classed as Critically Endangered or extirpated from the upper and middle reaches of the Danube River above the dams.
Other uses
Before 1800, swim bladders of sturgeon (primarily Beluga sturgeon from Russia) were used as a source of isinglass
Isinglass ( ) is a form of collagen obtained from the dried swim bladders of fish. The English word origin is from the obsolete Dutch ''huizenblaas'' – ''huizen'' is a kind of sturgeon, and ''blaas'' is a bladder, or German ''Hausenblase'', ...
, a form of collagen used historically for the clarification of wine
Wine is an alcoholic drink made from Fermentation in winemaking, fermented fruit. Yeast in winemaking, Yeast consumes the sugar in the fruit and converts it to ethanol and carbon dioxide, releasing heat in the process. Wine is most often made f ...
and beer
Beer is an alcoholic beverage produced by the brewing and fermentation of starches from cereal grain—most commonly malted barley, although wheat, maize (corn), rice, and oats are also used. The grain is mashed to convert starch in the ...
, as a predecessor for gelatin
Gelatin or gelatine () is a translucent, colorless, flavorless food ingredient, commonly derived from collagen taken from animal body parts. It is brittle when dry and rubbery when moist. It may also be referred to as hydrolyzed collagen, coll ...
, and to preserve parchments.
The Jewish laws of kashrut
(also or , ) is a set of Food and drink prohibitions, dietary laws dealing with the foods that Jewish people are permitted to eat and how those foods must be prepared according to halakha, Jewish law. Food that may be consumed is deemed ko ...
, which only permit the consumption of fish with both scales and fins, 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
Conservatism is a cultural, social, and political philosophy and ideology that seeks to promote and preserve traditional institutions, customs, and values. The central tenets of conservatism may vary in relation to the culture and civiliza ...
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.
Sturgeons were declared to be a royal fish under a statute dating back to 1324 by King Edward II of England
Edward II (25 April 1284 – 21 September 1327), also known as Edward of Caernarfon or Caernarvon, was King of England from 1307 until he was deposed in January 1327. The fourth son of Edward I, Edward became the heir to the throne follo ...
. Technically, the British monarchy still owns all sturgeons, whale
Whales are a widely distributed and diverse group of fully Aquatic animal, aquatic placental mammal, placental marine mammals. As an informal and Colloquialism, colloquial grouping, they correspond to large members of the infraorder Cetacea ...
s, and dolphin
A dolphin is an aquatic mammal in the cetacean clade Odontoceti (toothed whale). Dolphins belong to the families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), Pontopori ...
s that inhabit the waters around England
England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...
and Wales
Wales ( ) is a Countries of the United Kingdom, country that is part of the United Kingdom. It is bordered by the Irish Sea to the north and west, England to the England–Wales border, east, the Bristol Channel to the south, and the Celtic ...
. Under the law of the United Kingdom
The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Northwestern Europe, off the coast of European mainland, the continental mainland. It comprises England, Scotlan ...
, any sturgeons captured within the realm are personal property of the monarch.
Similar laws reserving sturgeon for the king were enforced in late medieval Denmark. An archaeological example of sturgeon in a royal context comes from the wreck of the Danish-Norwegian flagship, Gribshunden
''Gribshunden'' or ''Griffen'' (English language, English: "Griffin-Hound" or "Griffin"), also known by several variant names including ''Gribshund'', ''Gripshunden'', ''Gripshund'', ''Griff'', and ''Griffone'', was a Denmark, Danish warship, th ...
, which sank in June 1495 while King Hans sailed from Copenhagen to Kalmar, Sweden for a diplomatic summit. Archaeologists recovered from the wreck a cask containing a butchered sturgeon, probably intended for the king's table during feasts in Kalmar.
In heraldry, a sturgeon is the symbol on the coat of arms for Saint Amalberga of Temse.
Notes
* This article incorporates text from a publication now in the public domain
The public domain (PD) consists of all the creative work to which no Exclusive exclusive intellectual property rights apply. Those rights may have expired, been forfeited, expressly Waiver, waived, or may be inapplicable. Because no one holds ...
:
References
External links
FishBase info on Acipenser
Official website
of the World Sturgeon Conservation Society
PBS special, video clips and public outreach videos about sturgeon
{{Good article
Articles containing video clips
Commercial fish
Apex predators
Taxa named by Charles Lucien Bonaparte
Extant Maastrichtian first appearances