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''.
Two species (''
H. naccarii'' and ''
S. dabryanus'') may be
extinct in the wild, 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 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, 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''.
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''
(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''
(John Edward Gray, J. E. Gray, 1835) (Chinese sturgeon)
** ''Sinosturio transmontanus''
(John Richardson (naturalist), 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 & Julius Theodor Christian Ratzeburg, Ratzeburg, 1833 (native to eastern Europe, west Asia, and eastern North America)
** ''Huso baerii''
( J. F. Brandt, 1869) (Siberian sturgeon)
*** ''Acipenser baerii baicalensis, Huso baerii baicalensis''
(Alexander Mikhailovich Nikolsky, A. M. Nikolskii, 1896) (Baikal sturgeon)
*** ''Acipenser baerii stenorrhynchus, Huso'' ''Acipenser baerii stenorrhynchus, baerii stenorrhynchus''
(Alexander Mikhailovich Nikolsky, A. M. Nikolskii, 1896)
** ''Huso brevirostrum''
(Charles Alexandre Lesueur, Lesueur, 1818) (shortnose sturgeon)
** ''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)
** ''Huso gueldenstaedtii''
( J. F. Brandt & Julius Theodor Christian Ratzeburg, Ratzeburg, 1833) (Russian sturgeon)
** ''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''
(Charles Lucien Bonaparte, Bonaparte, 1836) (Adriatic sturgeon)
** ''Huso nudiventris''
(Aleksey Leontievitch Lovetsky, Lovetsky, 1828) (fringebarbel sturgeon)
** ''Huso persicus''
(Nikolai Andreyevich Borodin, 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)
** ''Huso stellatus''
(Peter Simon Pallas, Pallas, 1771) (starry sturgeon)
* Genus ''
Pseudoscaphirhynchus''
Alexander Mikhailovich Nikolsky, Nikolskii, 1900 (native to Central Asia)
** ''Pseudoscaphirhynchus fedtschenkoi''
(Karl Fedorovich Kessler, Kessler, 1872) (Syr Darya sturgeon)
** ''Pseudoscaphirhynchus hermanni''
(Karl Fedorovich Kessler, Kessler, 1877) (dwarf sturgeon)
** ''Pseudoscaphirhynchus kaufmanni''
(Karl Fedorovich Kessler, 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 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'')
** †''Acipenser albertensis, "Acipenser" albertensis''
Lawrence Lambe, 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, "''Acipenser anisinferos, ''Acipenser"'' Acipenser anisinferos, ''anisinferos''
Hilton & Grande, 2023 (Late Cretaceous of North Dakota, USA)
** †''Acipenser chilini, "Acipenser" chilini''
Nessov, 1983 (Early Paleocene of Kazakhstan)
** ?†''Acipenser cretaceous, "Acipenser" cretaceous''
Daimeries, 1892 (Late Cretaceous of Belgium; potentially a teleost)
** †''Acipenser eruciferus, "Acipenser" eruciferus''
Edward Drinker Cope, Cope, 1876 (Late Cretaceous of Montana, USA)
** †''Acipenser gigantissimus, "Acipenser" gigantissimus''
Nessov, 1997 (Late Cretaceous of Saratov, Russia)
** †''Acipenser lemoinei, "Acipenser" lemoinei''
(Priem, 1901) (Ypresian, Early Eocene of France)
** ?†''Acipenser molassicus, "Acipenser" molassicus''
Probst, 1882 (Miocene of Germany; potentially a Chondrichthyes, chondrichthyan)
** †''Acipenser ornatus, "Acipenser" ornatus''
Joseph Leidy, Leidy, 1873 (Miocene of Virginia, USA)
** †''Acipenser parisiensis, "Acipenser" parisiensis''
Priem, 1908 (Rupelian, Early Oligocene of France)
** †''Acipenser praeparatorum, "Acipenser" praeparatorum''
Hilton & Grande, 2023 (Late Cretaceous of North Dakota, USA)
** †''Acipenser toliapicus, "Acipenser" toliapicus''
Louis Agassiz, Agassiz 1844 ''ex'' Arthur Smith Woodward, Woodward 1889 (Early Eocene of England)
** ?†''Acipenser tuberculosus, "Acipenser" tuberculosus''
Probst 1882 (Miocene of Germany; potentially a chondrichthyan)
** †''Acipenser zhylgensis, "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 of Montana, USA)
*Genus †''Protoscaphirhynchus''
Wilimovsky, 1956
**†''Protoscaphirhynchus squamosus''
Wilimovsky, 1956 (Late Cretaceous of Montana, USA)
*Subfamily †Priscosturioninae Lance Grande,
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 ''Nomen dubium, 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, 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 to subarctic 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 to Newfoundland (island), Newfoundland, including the Great Lakes and the Saint Lawrence River, St. Lawrence, Missouri River, Missouri, and Mississippi Rivers, as well as along the West Coast in major rivers from California and Idaho to British Columbia. They occur along the European Atlantic coast, including the Mediterranean basin, especially in the Adriatic Sea and the rivers of North Italy; in the rivers that flow into the Black Sea, Black, Azov Sea, Azov, and Caspian Sea, Caspian Seas (Danube, Dnieper, Dnepr, Volga, Ural River, Ural and Don River (Russia), Don); the north-flowing rivers of Russia that feed the Arctic Ocean (Ob River, Ob, Yenisei, Lena River, Lena, Kolyma River, 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-China, Chinese border, on Sakhalin 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, overfishing, and pollution.
No species is 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
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 ...
, Spawn (biology), spawning 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 (''Acipenser fulvescens'') and the Baikal sturgeon (''A. baerii baicalensis''), or have been forced into them by human or natural dam, 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.
Physical characteristics

Sturgeons retain several primitive characteristics from the bony fishes. Along with other members of the subclass (biology), subclass Chondrostei, they are unique among bony fishes because their skeletons are almost entirely cartilaginous. To maintain structure, sturgeons are one of few organisms to retain a post-embryonic notochord 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 Body of vertebra, vertebral centra, and are partially covered with five lateral rows of scutes rather than Fish scale, scales.
They also have four barbels—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 Rostrum (anatomy), rostra, 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 sturgeon, beluga (''Huso huso'') in the Caspian Sea 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, 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.
Sturgeons are polyploidy, polyploid; 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 (biology), 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 (marine biology), substrate, where the eggs can adhere, and proper water temperature and flow for Oxygenation (environmental), 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 oxbow lake, oxbows and Slough (hydrology), sloughs, where the free-swimming Fry (biology), fry spend their first year feeding on insect larvae and crustacea. 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 zone, benthic 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. Having no teeth, they are unable to seize prey, though larger individuals and more predatory species can swallow very large prey items, including whole salmon. 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 using their ampullae of Lorenzini.
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, 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 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, 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. They were in such abundance in the Hudson River that they were Culinary name#Humor, 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 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. 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 since 1998.
Conservation
Sturgeons are threatened by the negative impacts of overfishing, poaching, habitat destruction, 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 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 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, a form of collagen used historically for the Clarification (wine), clarification of wine and beer, as a predecessor for gelatin, and to preserve parchments.
The Jewish laws of kashrut, which only permit the consumption of fish with both scales and fins, forbids sturgeon, as they have ganoid scales instead of the permitted Ctenoid scale, ctenoid and cycloid scales. While all Orthodox Judaism, Orthodox groups forbid the consumption of sturgeon, some Conservative Judaism, 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.
Sturgeons were declared to be a royal fish under a statute dating back to 1324 by King Edward II of England. Technically, the British monarchy still owns all sturgeons, whales, and dolphins that inhabit the waters around England and Wales. Under the law of the United Kingdom, 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, 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:
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
Sturgeons,
Articles containing video clips
Commercial fish
Apex predators
Taxa named by Charles Lucien Bonaparte
Extant Maastrichtian first appearances