View source for Sterlet

{{Taxobox
| name = Sterlet
| image = Acipenser ruthenus Prague Vltava_1.jpg
| image_caption = 
| status = VU
| status_system = IUCN3.1
| status_ref = <ref name=IUCN>{{IUCN |assessor=Gesner, J. |assessor2=Freyhof, J. |assessor3=Kottelat, M. |last-assessor-amp=yes |year=2010 |id=227 |taxon=Acipenser ruthenus |version=2012.2}}</ref>
| regnum = [[Animal]]ia
| phylum = [[Chordate|Chordata]]
| classis = [[Actinopterygii]]
| ordo = [[Acipenseriformes]]
| familia = [[Acipenseridae]]
| genus = ''[[Acipenser]]''
| species = '''''A. ruthenus'''''
| binomial = ''Acipenser ruthenus''
| binomial_authority = [[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]
}}

The '''sterlet''' (''Acipenser ruthenus'') 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 River|Yenisei]]. Populations migrating between fresh and salt water ([[anadromous]]) have been [[extirpated]].<ref name=IUCN/>

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

==Physical appearance==
*The sterlet may reach 16&nbsp;kg in weight and 100 to 125&nbsp;cm in length, rarely exceeding a length of 3&nbsp;ft.
*It is quite variable in coloration, but usually has a yellowish [[ventral]] side. 
*It is distinguishable from other European species of sturgeons by the presence of a great number of whitish lateral [[scutes]], fringed [[barbel (anatomy)|barbel]]s, 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]], [[worm]]s, and insect [[larva]]e.
[[File:Acipenser ruthenus Prague Vltava_3.jpg|thumb|300px|left|On exhibition Subaqueous Vltava, Prague]]

==Life history==
[[File:Acipenser ruthenus3.jpg|thumb|]]
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 15,000–44,000 eggs, at water temperatures preferably 12–17&nbsp;°C (54–63&nbsp;°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.

==As food==
[[File:Sterlet with satsivi.JPG|thumb|Sterlet with [[Walnut sauce|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]].

==Sturgeon hybrids==
*Sterlet x Beluga (''Huso huso'') = (Bester) 
*Sterlet x Siberian [Russian] Sturgeon (''Acipenser gueldenstaedtii'')]
*Sterlet x Diamondback 
*Hybrids are hardier than their parents.{{citation needed|date=June 2014}}

==References==
{{Reflist}}

{{Acipenseriformes}}

[[Category:Freshwater fish of Europe]]
[[Category:Fish of Europe]]
[[Category:Fish of the Black Sea]]
[[Category:Fauna of Kazakhstan]]
[[Category:Fish of Russia]]
[[Category:Animals described in 1758]]


{{Acipenseriformes-stub}}