Sturgeon (from Old English styrġa ultimately from Proto-Indo-European *str̥(Hx)yón-[1]) is the common name for the 28 species of fish belonging to the family Acipenseridae.

The family is grouped into four genera: Acipenser (which is paraphyletic, containing many distantly related sturgeon species), Huso, Scaphirhynchus, and Pseudoscaphirhynchus.

[4] Sturgeons are long-lived, late-maturing fishes with distinctive characteristics, such as a heterocercal caudal fin similar to those of sharks, and an elongated, spindle-like body that is smooth-skinned, scaleless, and armored with five lateral rows of bony plates called scutes.

The largest sturgeon on record was a beluga female captured in the Volga Delta in 1827, measuring 7.2 m (23 ft 7 in) long and weighing 1,571 kg (3,463 lb).

This has led to serious overexploitation, which combined with other conservation threats, has brought most of the species to critically endangered status, at the edge of extinction.

[5] True sturgeons appear in the fossil record during the Upper Cretaceous, with amongst the oldest known remains being a partial skull from the Cenomanian (100–94 million years ago) of Alberta, Canada.

[6] 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.

[7][8] This is explained in part by the long generation interval, tolerance for wide ranges of temperature and salinity, 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.

[9] Despite the existence of a fossil record, full classification and phylogeny 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.

[13] Coelacanths, lungfish Tetrapods Polypteriformes (bichirs, reedfishes) Acipenseridae Polyodontidae Lepisosteiformes (gars) Amiiformes (bowfins) Teleostei In currently accepted taxonomy, the class Actinopterygii and the order Acipenseriformes are both clades.

This list uses the original classification scheme: Family Acipenseridae Sturgeon range from subtropical to subarctic waters in North America and Eurasia.

[21][16] Throughout this extensive range, almost all species are highly threatened or vulnerable to extinction due to a combination of habitat destruction, overfishing, and pollution.

[21] 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.

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.

[35] The sturgeons' electroreceptors are located on the head and are sensitive to weak electric fields generated by other animals or geoelectric sources.

In 1731, an observer of leaping sturgeon wrote: ...in May, June and July, the rivers abound with them, at which time it is surprising, though very common to see such large fish elated in the air, by their leaping some yards out of the water; this they do in an erect posture, and fall on their sides, which repeated percussions are loudly heard some miles distance....[39]Globally, sturgeon fisheries are of great value, primarily as a source for caviar, but also for flesh.

They were in such abundance in the Hudson River that they were humorously called "Albany beef" and sturgeon eggs were given away at local bars as an accompaniment to 5¢ beer.

[45] 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.

[43] 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.

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.

[68] 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.

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.