The bastard sturgeon, also known as the fringebarbel sturgeon, ship sturgeon, spiny sturgeon, or thorn sturgeon (''Huso nudiventris''), is a species of fish in the 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 ...

. These fish are typically found along 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.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 ...

Taxonomy

Prior to 2025, it was placed in 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 ...

'', but this placement was found to be

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 ...

, and it is more accurately placed in the 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 ...

''.

Feeding

''Huso nudiventris'' typically feed on other animals near 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.mollusks Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The num ...

crustacean 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 ...

s, and other smaller fish.

Reproduction

''Huso nudiventris'' are usually anadromous—meaning they live in saltwater and travel to freshwaters to deposit eggs—but some can spend their entire life cycle in freshwater. Because they travel from saltwater to freshwater to spawn, they often live nearby estuaries. Migration to freshwaters for deposition of eggs occurs during spring between the months of March and May, and fall between October and November. On average, female bastard sturgeon produce between 200,000 and 300,000 eggs over the course of their lifetime. The young ''Huso nudiventris'' can live in freshwater for years following birth prior to traveling to the sea, though many migrate to the sea soon after birth. The average time between birth of subsequent ''Huso nudiventris'' is around 15 years; variation in generation time of this species is somewhat dependent on human fishing patterns and whether the species is thriving in its environment.

Conservation status

Formerly abundant in 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 ...

, Aral and Caspian seas, its range is now primarily limited to the

Ural River The Ural, also known as the Yaik , is a river flowing through Russia and Kazakhstan in the continental border between Europe and Asia. It originates in the southern Ural Mountains and discharges into the Caspian Sea. At , it is the third-longes ...

(in

Russia Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders ...

and

Kazakhstan Kazakhstan, officially the Republic of Kazakhstan, is a landlocked country primarily in Central Asia, with a European Kazakhstan, small portion in Eastern Europe. It borders Russia to the Kazakhstan–Russia border, north and west, China to th ...

), with possible

relict A relict is a surviving remnant of a natural phenomenon. Biology A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. Geology and geomorphology In geology, a r ...

populations in the Rioni River in

Georgia Georgia most commonly refers to: * Georgia (country), a country in the South Caucasus * Georgia (U.S. state), a state in the southeastern United States Georgia may also refer to: People and fictional characters * Georgia (name), a list of pe ...

and the Safid Rud in

Iran Iran, officially the Islamic Republic of Iran (IRI) and also known as Persia, is a country in West Asia. It borders Iraq to the west, Turkey, Azerbaijan, and Armenia to the northwest, the Caspian Sea to the north, Turkmenistan to the nort ...

. One of the most established populations is one in Lake Balkhash in

, well outside its natural range, where they were introduced in the 1930s for commercial purposes. A decline in the abundance of ''Huso nudiventris'' has been reported due to overfishing and damming, which have led to limitations placed on fishing for bastard sturgeon in areas such as the

. In order to alleviate concerns with rapidly decreasing ''Huso nudiventris'', an effort was made to raise these fish in captivity before releasing them back into rivers they once inhabited. Acipenser nudiventris head

References

Acipenser Fish of the Black Sea Fish of the Caspian Sea Fish of the Sea of Azov Aral Sea Fish of Europe Fish of West Asia Critically endangered fish Critically endangered fauna of Asia Critically endangered biota of Europe Taxonomy articles created by Polbot Fish described in 1828 {{Acipenseriformes-stub