Sterlet

Not to be confused with Starlet.

Sterlet
Conservation status
Endangered  (IUCN 3.1) [1]
CITES Appendix II (CITES) [2]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Actinopterygii
Order:	Acipenseriformes
Family:	Acipenseridae
Genus:	Huso
Species:	H. ruthenus
Binomial name
Huso ruthenus (Linnaeus, 1758)
Range of A. ruthenus   Resident   Extinct
Synonyms [3] [4]
List Acipenser pygmaeusPallas 1814 non Reisinger 1830  ?Acipenser kosteraFitzinger 1832  ?Acipenser kosterGmelin 1774 nomen nudum Acipenser marsigliiBrandt 1833 Acipenser kamensisLovetsky 1834 Acipenser gmeliniFitzinger 1836 Acipenser aleutensisFitzinger 1836 Acipenser dubiusHeckel 1836  ?Acipenser ruthenus var. leucoticaBrandt 1853 Acipenser ruthenus var. grisescensBrandt 1853 Acipenser (Sterletus) kankreniValenciennes ex Duméril 1870 Acipenser (Sterletus) lovetzkyiDuméril 1870 Sterledus ruthenus var. sibiricusDybowski 1874 Acipenser jeniscensisHerzenstein 1895 Acipenser ruthenus var. albineaBrusina 1902 Acipenser ruthenus var. birostrataBrusina 1902 Acipenser ruthenus var. obtusirostraBrusina 1902 non Lovetsky 1834 Acipenser ruthenus var. septemcarinataBrusina 1902 Acipenser ruthenicusBrusina 1902 Acipenser sterletBrusina 1902 Acipenser sterletaGüldenstädt 1772 Acipenser ruthenus var. albusAntipa 1909 Acipenser ruthenus var. erytraeaAntipa 1909 Acipenser ruthenus var. brevirostrisAntipa 1909 Acipenser ruthenus ruzskyiJohansen 1946 Acipenser ruthenus ruzskyi n. baschmakovaeJohansen 1946 Acipenser kosterusFitzinger 1832 Euacipenser ruthenus(Linnaeus 1758) Sterledus ruthenus sibiricusDybowski 1874 Sterleta ruthena(Linnaeus 1758) Sterletae ruthena(Linnaeus 1758) Sterletus ruthenus(Linnaeus 1758)

The sterlet (Huso ruthenus) ^[5] 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. Populations migrating between fresh and salt water (anadromous) have been extirpated. ^[1] It is also known as the sterlet sturgeon.

Due to overfishing (for its flesh, caviar, and isinglass), pollution, and dams, the sterlet has declined throughout its native range and is considered vulnerable by the IUCN. Restocking projects are ongoing, and it has been introduced to some regions outside its native range, but the latter have generally not become self-sustaining. Today, the majority of the international trade involves sterlets from aquaculture. ^[1]

Taxonomy

Prior to 2025, it was placed in the genus Acipenser , but this placement was found to be paraphyletic, and it is more accurately placed in the genus Huso . ^{[5] [6]}

Physical appearance

The sterlet may reach 16 kg in weight and 100 to 125 cm in length, rarely exceeding a length of 90 cm. It is quite variable in coloration, but usually has a yellowish ventral side.

It can be distinguished from other European species of sturgeons by the presence of a great number of whitish lateral scutes, fringed barbels, and an elongated and narrow snout, highly variable in length.

Feeding habits

The sterlet's main source of food is benthic organisms; they commonly feed on crustaceans, worms, and insect larvae. ^[7]

On exhibition Subaqueous Vltava, Prague

Life history

The sterlet commonly reaches the age of 22 to 25 years. Males reach sexual maturity at 3–7 years old and females at 4–12 years old. Spawning occurs from the middle of April to the beginning of June. Females may lay from 15,000 to 44,000 eggs, at water temperatures preferably 12–17 °C (54–63 °F).

As pond fish

Sterlets require relatively large ponds with good water conditions, and may get entangled in plants such as blanketweed. They may require special food such as sterlet sticks, as they are unable to digest the vegetable proteins usually found in commercial fish foods.^{[ citation needed ]}

As food

Sterlet with satsivi

In Russia, it is held in high esteem on account of its excellent flesh, contributing also to the best kinds of caviar and isinglass.^{[ citation needed ]}

History in the Danube

The sterlet (Acipenser ruthenus in Linnaeus' classification) is the last of the five native sturgeon species inhabiting the Middle and Upper Danube River. Its population has dropped significantly, mainly due to the degradation of main habitats, spawning grounds and foraging grounds. ^[8]

References

1. Gessner, J.; Freyhof, J.; Kottelat, M.; Friedrich, T. (2022). "Acipenser ruthenus". IUCN Red List of Threatened Species . 2022: e.T227A135062526. Retrieved 2 August 2022.
2. "Appendices | CITES". cites.org. Retrieved 2022-01-14.
3. Froese, R.; Pauly, D. (2017). "Acipenseridae". FishBase version (02/2017). Retrieved 18 May 2017.
4. "Acipenseridae" (PDF). Deeplyfish- fishes of the world. Retrieved 18 May 2017.
5. Eschmeyer, William N.; Fricke, Ron & van der Laan, Richard (eds.). "Species in the genus Huso". Catalog of Fishes . California Academy of Sciences . Retrieved 28 May 2025.
6. Brownstein, Chase D.; Near, Thomas J. (2025-04-25). "Toward a Phylogenetic Taxonomy of Sturgeons (Acipenseriformes: Acipenseridae)" . Bulletin of the Peabody Museum of Natural History. 66 (1). doi:10.3374/014.066.0101. ISSN   0079-032X.
7. "What Do Sturgeon Fish Eat?". Sciencing. Retrieved 2022-04-29.
8. Kubala, Maroš; Farský, Martin; Pekárik, Ladislav (February 2019). "Migration patterns of sterlet (Acipenser ruthenus, Linnaeus 1758) in the Middle Danube assessed by 1 year acoustic telemetry study". Journal of Applied Ichthyology. 35 (1): 54–60. doi: 10.1111/jai.13859 . ISSN   0175-8659.