mainpage infobase aboutus links contact

Sterlet - Acipenser ruthenus

Sterlet reaches length of 125 cm, and weight of 16 kg. It represents the smallest sturgeon species in the Danube River. It has 11-18 dorsal scutes, 56-71 lateral scutes, and 10-20 ventral scutes. Sterlet differs from the ship sturgeon by its lower lip, which is interrupted in its center, while it differs from other sturgeon species by fimbriated barbels and a larger number of lateral scutes. Length of the rostrum varies, but it is usually 37-49 % of the total head length.

Sterlet is exclusively potamodromous species, and inhabits river areas in lowlands. It is Eurasian species and dwells in rivers that belong to Caspian, Black, Azov, Baltic and Artic Sea basins. Sterlet used to be present in the Danube River as far as Ulm and Regensburg. Sterlet usually resides in the mainstream of the river flow, in deeper depressions of the river bottom, above stone, gravelly or sandy bottom. During spring rise of water level, sterlet moves to flooded areas in search of food. During winter it stays in groups in depresions of river botom, with minimum daily activity.


Maximum recorded age is 26 years. Males become sexually mature at 3 - 5 years and females at 4 - 7 years of age. It is believed that the younger individuals spawn each year, while the older individuals spawn every second year. In the Danube River, spawning lasts during April and May, at the time of high water level, at the temperature level of 8-19 ºC, on the depth up to 10 m. Sterlet spawns on gravelly ground with fast river flow, on the river bottom as well as in flood areas during spring floods. Although it is a resident species, it migrates upstream during spring floods for spawning.
Sterlet catch decrease

Basic sterlet food are different benthic organisms, mostly insect larvae, mainly Chironomidae, Trichoptera, Ephemeroptera and Simuliidae. It feeds also on larvae of Plecoptera and Heleidae, small mollusks from the genera Sphaerium, Pisidium and Viviparus, and representatives of Oligochaeta, Polychaeta, Hirudinea and other benthic invertebrates. During the spawning period of other fish species, significant part of sterlet diet are eggs of those species.

Sterlet range; green area - present, red area - extinct (

Temporary ban on sterlet catch is established for the period from the 1st of March until 31st of May, while the minimum prescribed length for catch is 40 cm (“Official Gazette of Republic Serbia“, No 36/09).


Source: Lenhardt, M., Hegediš, A. and Jaric, I. (2005). Action plan for sturgeon species management in fishery waters of Republic Serbia. Institute for Biological Research “Siniša Stankovic”, p. 21. Developed for Ministry of Science and Environmental Protection of Republic Serbia.

Internet presentation was funded by Minstry of Environmental Protection of Republic Serbia. Webdesign & maintenance: Ivan Jarić