Sturgeon is the common name for 28 species offish in the familyAcipenseridae . The family has four extantgenera :Acipenser Huso Scaphirhynchus Pseudoscaphirhynchus beluga ), are harvested for their valuablecaviar .
Sturgeons are known for their longbody , which contains dozens of plates calledscutes . They have a sharpsnout and a heterocercal tail.
Sturgeons have been referred to as "living fossils " or "primitive fish" because their features have not changed very much since their earliest fossil record.[ 1] [ 2]
Acipenseriformes first appeared 174–201 mya. Then, the "true" sturgeons appeared in theUpper Cretaceous .
FamilyAcipenseridae (sturgeons)
GenusAcipenser Linnaeus, 1758 †Acipenser albertensis Lambe 1902 > Acipenser baerii J. F. Brandt, 1869 (Siberian sturgeon)Acipenser baerii baicalensis A. M. Nikolskii, 1896 (Baikal sturgeon)Acipenser baerii stenorrhynchus A. M. Nikolskii, 1896 Acipenser brevirostrum Lesueur, 1818 (Shortnose sturgeon)Acipenser dabryanus A. H. A. Duméril, 1869 (Yangtze sturgeon)†Acipenser cruciferus (Cope 1876) †Acipenser eruciferus Cope 1876 Acipenser fulvescens Rafinesque, 1817 (Lake sturgeon)†Acipenser gigantissimus Nessov 1997 Acipenser gueldenstaedtii J. F. Brandt & Ratzeburg, 1833 (Russian sturgeon)Acipenser medirostris Ayres, 1854 (Green sturgeon)Acipenser mikadoi Hilgendorf, 1892 (Sakhalin sturgeon)†Acipenser molassicus Probst 1882 Acipenser naccarii Bonaparte, 1836 (Adriatic sturgeon)Acipenser nudiventris Lovetsky, 1828 (Fringebarbel sturgeon)†Acipenser ornatus Leidy 1873 Acipenser oxyrinchus Mitchill, 1815 Acipenser persicus Borodin, 1897 (Persian sturgeon)Acipenser ruthenus Linnaeus, 1758 (Sterlet)Acipenser schrenckii J. F. Brandt, 1869 (Japanese sturgeon)Acipenser sinensis J. E. Gray, 1835 (Chinese sturgeon)Acipenser stellatus Pallas, 1771 (Starry sturgeon)Acipenser sturio Linnaeus, 1758 (European sea sturgeon)†Acipenser toliapicus Agassiz 1844 ex Woodward 1889 Acipenser transmontanus J. Richardson, 1836 (White sturgeon)†Acipenser tuberculosus Probst 1882 GenusHuso J. F. Brandt & Ratzeburg, 1833 GenusScaphirhynchus Heckel, 1835 Scaphirhynchus albus (Forbes & R. E. Richardson, 1905) (Pallid sturgeon)Scaphirhynchus platorynchus (Rafinesque, 1820) (Shovelnose sturgeon)Scaphirhynchus suttkusi J. D. Williams & Clemmer, 1991 (Alabama sturgeon) GenusPseudoscaphirhynchus Nikolskii, 1900 Pseudoscaphirhynchus fedtschenkoi (Kessler, 1872) (Syr Darya sturgeon)Pseudoscaphirhynchus hermanni (Kessler, 1877) (Dwarf sturgeon)Pseudoscaphirhynchus kaufmanni (Kessler, 1877) (Amu Darya sturgeon) Beluga sturgeon (Huso huso )Sturgeon range fromsubtropical to subarctic waters inNorth America andEurasia . InNorth America , they range along theAtlantic coast from theGulf of Mexico toNewfoundland . They used to be found throughout theMississippi River, theGreat Lakes and theHudson River .
Throughout this extensive range, almost all species are highly threatened or vulnerable to extinction due to a combination ofhabitat destruction ,overfishing , and pollution.[ 3]
In the last century, this large fish was often regarded as a nuisance because it often became entangled in and caused commercial fishing nets to become ripped. Only much later did the sturgeon become prized for itsmeat ,eggs (caviar) andoil .Gelatin from the inner lining of its air bladder was used to makeisinglass –a substance used as a clarifying agent in jellies, glues and in the isinglass windows of carriages and early cars. Nowadays, the lake sturgeon's dark form can be sometimes be discerned in reedyshallows or near river mouths.
Lake sturgeon (Acipenser fulvescens )Pallid sturgeon (Scaphirhynchus albus )Siberian sturgeon (Acipenser baerii )↑ Chesapeake Bay Field Office."Atlantic Sturgeon" . U.S. Fish & Wildlife Service. Archived fromthe original on June 15, 2019. RetrievedJune 10, 2014 . ↑ "Lake sturgeon" . Minnesota Dept. of Natural Resources. RetrievedJune 10, 2014 .↑ Sturgeon more critically endangered than any other group of species.IUCN, the International Union for Conservation of Nature .[1] Acipenser albertensis 
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