Water parameters
Minimum tank: 2500 L per individual at harvest size.
Feed and growth
- Feed protein
- 45% target
- Daily feed (warm)
- 1.00% of body weight
- Daily feed (cool)
- 0.50% of body weight
- Max density
- 35 g per litre
A 6000 g adult eats about 60.0 g of feed per day at optimum. 10 fish at adult size: ~600 g daily.
Legality
Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.
| Jurisdiction | Status | Notes |
|---|---|---|
| Worldwide | restricted | CITES Appendix II; international trade requires permits verified 2026-05-13 |
| California | prohibited | verified 2026-05-13 |
| European Union (bloc) | permit required | Aquaculture established in Hungary, Italy, Germany; permits via CITES authority verified 2026-05-13 |
Unlisted jurisdictions default to "check local regulations".
Origin and habitat
Native to rivers draining into the Caspian Sea, Black Sea, Sea of Azov, and the Baltic Sea, including the Volga, Danube, Don, Ob, and Yenisei. The species (Acipenser ruthenus) is the smallest commonly cultured sturgeon, reaching 1–1.2 m and 5–16 kg, significantly smaller than Russian sturgeon or beluga. Sterlet are among the few sturgeon species that spend their entire life in freshwater (most sturgeons are anadromous or semi-anadromous). They mature faster than larger sturgeon species: females can produce roe at 5-8 years, compared to 10-15 years for Russian sturgeon. Sterlet caviar is a mid-range premium product ($100-300/kg retail). Wild populations have declined substantially due to river damming and overfishing. The species is the most commonly kept ornamental sturgeon in garden ponds in Europe.
Climate and outdoor ponds
- Climate
- cold-water (cool water required, dies in heat)
- USDA zones
- 3–8 (winter low around -40°C or warmer)
- Heating needed
- no
- Cooling needed
- yes, if summer water exceeds upper tolerance
Care notes
The most practical sturgeon species for smaller-scale aquaponics, thanks to the relatively small adult size and earlier maturity compared to larger sturgeons. Temperature range: 4–22°C, optimal at 14–18°C. Growth on sturgeon pellet (42-48% protein) is moderate: reaching 1–2 kg in 3-4 years. FCR is 1.3-1.8. Dissolved oxygen above 6 mg/L (sterlet are more oxygen-demanding than most fish). Ammonia below 0.5 mg/L. Stocking density in RAS: 15-30 g/L. For meat production, harvest at 0.5–1 kg (2-3 years) is viable; for caviar, females need 5-8 years. The bester hybrid (beluga x sterlet) is also farmed commercially and combines sterlet's smaller size with some of beluga's faster growth. Sterlet are bottom feeders that require sinking pellet; they don't feed at the surface. The mouth is ventral and protrusible, adapted for vacuuming food from the substrate. Tank design should minimize sharp edges because sterlet have soft, scaleless skin that damages easily. Fingerlings are available from sturgeon farms in Europe (particularly Germany, Austria, and Hungary) and from some US sturgeon operations. CITES regulations may apply to international trade. For European aquaponics operators wanting a cold-water species with caviar potential on a shorter timeline than Russian sturgeon, sterlet is the best option.