Technology - RAS for sturgeon

Technology for growing sturgeon in RAS systems

RAS allows you to raise sturgeon all year round - for meat or caviar - with complete control of temperature, oxygen and hydrochemistry. We analyze the environmental parameters, design features, growth, feed and breeding scheme for caviar.

Sturgeon in the RAS pool
Commercial sturgeon in the RAS basin
Short answer

Sturgeon farming in RAS explains how to organize fish production with controlled water quality, oxygen, temperature, stocking density, feeding and routine operations. Sturgeon technology requires accurate bottom area, oxygen, solids removal, biofiltration and redundancy calculations because the cycle is long.

What is a sturgeon RAS farm?

A RAS sturgeon farm is a farm with repeated use of water, where the quality of the environment is maintained by a cleaning and preparation system: mechanical cleaning, biofiltration, oxygenation, and, if necessary, ozone and pH correction. This makes it possible to grow sturgeon all year round by controlling temperature, oxygen and hydrochemistry.

History and types

Artificial breeding of sturgeon dates back to 1869 year, when on the Volga near Simbirsk F. V. Ovsyannikov was the first to carry out artificial fertilization of sterlet eggs. In the late 1970s, Soviet biotechnology for commercial sturgeon farming came to the United States and Western Europe; Today the direction is also developing in China and other countries.

Types for commercial RAS

  • Siberian sturgeon (Lena population)
  • Russian sturgeon
  • Bester
  • Sterlet
  • Russian-Lena hybrid (Ro×Lo)
  • Beluga (less often - long maturation period for caviar)

Growing conditions are similar; differences are in growth rates, marketable weight and ripening periods.

Farm options

Ponds

Simple infrastructure, but strong seasonality and dependence on climate and water quality.

cages

Growing in ponds; depends on temperature, oxygen and water use rules.

Forward flow

On a constant influx; simpler, but critically tied to the flow rate and quality of the source.

RAS

Maximum controllability and year-round use; higher demands on engineering and discipline.

Basic Environment Settings

ParameterNorm/optimumComment
T (incubation)Russian sturgeon 12–16, beluga 12–14, stellate sturgeon 19–21, sterlet 12–14 °CFluctuation ≤2 °C/day, ≤0.2–0.3 °C/hour The mode is stable.
T (height)22–24 °CAbove 24–26 °C - decreased nutrition and growth.
O₂incubation/larval efflux ≥7.5–8; adults ≥7 mg/lCritical threshold 5 mg/l.
NH₃MAC 0.05 (fish), 0.025 mg/l (larva)Toxicity increases with pH and temperature.
NO₂⁻product 0.4 mg/lBriefly up to 1 mg/l.
NO₃⁻20–30 (juveniles) … 150–200 mg/l (product)
CO₂≤10 mg/lUp to 50 mg/L is tolerated when growth and FCR are impaired.
pH7–8 (in RAS ~7)Critical <6 and >9.
Suspension (TSS)up to 25 mg/l (product up to 30)
IronFe²⁺≤0,1; Fe³⁺≤0,9 mg/lPlaque on the gills, risk of death of fry.
H₂Snot allowLethal ~1 mg/l.
Salinityfresh / up to 20‰

Design Features

  • Sturgeon - bottom fish: water depth larva 30–40 cm, juveniles 70–80 cm, product and RMS ~100 see
  • Maximum diameter of pools 7–8 m: with more, self-cleaning deteriorates.
  • Water exchange: 1 revolution/hour for every 40–45 kg/m³ of fish.
  • Drum filter: 40 µm (small fish) and 60 µm (product/RMS).
  • Biofilter (22–24 °C): 0,5 g TAN for 1 m² of protected loading area per day.
  • Light feces: Traps and hydrocyclones are often ineffective - static loading (mech-bio filter) is recommended for transparency.
  • Densities: product 60–70 kg/m³; RMS 40–50 kg/m³.
  • Degassing often not necessary if the biofilter is well aerated.

Growth of sturgeon in RAS

Estimated: ~14 months to 2 kg (Russian/Siberian/Bester) and ~16 months up to 1.5 kg (sterlet). The curve below is an example from a production table.

05001000150020002500 12345678910111213141516171819 Weight, g (end of month) Growing month
StageRussian / Siberian / BesterSterlet
Caviar (“eye”) → 3 g40–55 days50–70 days
3 → 60 g55–65 days75–85 days
60 → 500 g150–180 days200–230 days
500 g → product180–210 days (up to 2–2.3 kg)120–150 days (up to 1.5 kg)

Stages of the commercial cycle

Incubation and maintenance of prelarvae. Incubators "Sturgeon", Weiss, McDonald. Incubation 6–9 days; O₂ ≥7.5 mg/l (outflow), control T every 2 hours. Aging: Russian sturgeon 8–10 days, beluga 12–16, sterlet 5–6.

Larva. Trays, pools ICA. 2–3 weeks up to 500 mg. T: Russian sturgeon 17–20 °C, beluga/sterlet 12–14, by the end of growing it is brought to 20–24.

Juvenile and commercial fish. Round (or square with rounded corners) and rectangular pools. T 18–26 °C, in RAS it is usually 22–24.

Specific oxygen consumption (SOC)

Weight, gURC, mg/(kg h)
1–3550
3–30470
30–100430
100–500380
500–1000350
1000–1500320
1500–2000300
2000–3000280
3000+260

Daily feed intake

Hitch% by weight
up to 5 g8–12%
5–50 g4–5%
50–100 g3–3,5%
200–800 g1,5–2%
800 g–1.5 kg1,2–1,5%
1,5–3 kg1–1,2%

Growing for caviar

A separate direction with its own broodstock economics and a long cycle.

Strategies for obtaining caviar

  • Bottomhole: more expensive, more broodstock required.
  • Lifetime: smaller herd and lower cost, but part of the market is skeptical.
  • Hybrid: several milkings (often 2), then slaughter - balancing costs and margins.
Sturgeon in a round pool
Broodstock guide
1 t of caviar/year ≈ 30 tons of herd (bottom hole) or ≈ 15 t (hybrid).

Manufacturer life cycle

Up to 700–800 g (~9–10 months): selection of leaders by growth (~50% of the herd).

Up to ~2.5 kg (~1.5 years): Ultrasound sex determination, males - for culling, females - for rearing.

Up to manufacturer's age (3–6 years): Ultrasound control of maturation, preparation for wintering.

Wintering 4–6 °C (~2 months, without feeding) with periodic ultrasound monitoring.

Spawning: temperature rise to ~20 °C, stimulation, milking of eggs.

Recovery 6–18 months and repeated cycles; after a few - slaughter (according to strategy).

StageKey parametersStern
Juveniles10–30 kg/m³; D=2–3 m; T 20–24; O₂>8; NH₄<2; NO₂<0,4; NO₃<100protein 50–60% / fat 15%
Product50–70 kg/m³; D=3–8 m; T 20–24; O₂>7; NH₄<4; NO₂<1; NO₃<200protein 45–50% / fat 10–15%
RMS40–50 kg/m³; D=3–8 m; T 20–24; O₂>7; NH₄<2; NO₂<0,7; NO₃<150protein 50–52% / fat 10–15%
Wintering40–50 kg/m³; T 4–6; O₂>7; NH₄<2; NO₂<0,7; NO₃<150
Getting caviar40–50 kg/m³; T 4→20; O₂>7; NH₄<2; NO₂<0,7; NO₃<150

Truss composition and equipment

Typical sturgeon RAS blocks. For eggs, RMS, wintering (chiller) and spawning (heating) are added.

  • Incubation/larva (if “from the calf”)
  • Raising juveniles
  • Product area
  • RAS core: mechanical cleaning, biofilter, pumps, oxygenation, automation
  • For caviar: RMS + wintering (chiller) + spawning (heating)
Pool hall of the sturgeon farm RAS
Fish tanks
Drum filter
Biofilter (floating load)
Mech-bio filter (sinking)
Pumps
O₂
Oxygenation
Ozonation system
pH
pH adjustment
Monitoring + autofeeding

Resource costs

Electricity

Pumps, oxygen/aeration, automation; for caviar - chiller and heating in blocks.

💧

Water

Make-up + drum rinsing + maintenance drains.

Stern

Main OPEX; norms according to tables, control over palatability and water.

Planting material

Caviar or juveniles - depending on the type and direction.

Staff

Fish farmer + RAS engineer/operator; for caviar - a specialist in ultrasound and working with producers.

Dimensions of fish tanks

StageOptimal, m³Allowable, m³
Larva up to 500 mgup to 20up to 30
Baby up to 3 g30–40up to 50
Juveniles up to 60 gup to 60up to 100
Commercial fishup to 150up to 200
~65%
Final survival rate (caviar → product)
~1,3
Final Feed Ratio (FCR)
~14 months
Up to 2 kg (Russian/Siberian/Bester)
60–70
kg/m³ - density on the product

Project implementation

Technology design — our profile (service “Design of fish farms”).

Building design.

Supply of equipment.

Construction of a building.

Installation of technology.

Launch and stocking.

Completed projects

Sturgeon RAS farms that we sold: Azerbaijan (100 t), Georgia (50 t), Kazakhstan (20 t), Moscow region, Krasnodar region, as well as a farm on 1 tons of caviar/year in Moldova.

Round pools of the sturgeon farm Pool hall of the sturgeon farm Sturgeon farm pools, Kazakhstan Round pools with sturgeon
FAQ

Frequently asked questions

Clear answers to the questions that usually appear before a RAS fish farm project starts.

Which parameters are critical for sturgeon farming in ras?

The critical parameters are temperature, dissolved oxygen, pH, ammonia, nitrite, nitrate, stocking density, feeding rate, hydraulics and redundancy of key equipment.

Can standard equipment be used without calculation?

It is risky. Equipment must match the species, biomass, feed load, water quality and building layout. A generic set can lead to weak filtration, unstable oxygen or difficult maintenance.

How is the technology selected for a project?

The choice depends on fish species, target capacity, water source, climate, available building, energy costs, staff skills, market format and the required level of automation.

Calculate a sturgeon farm to suit your conditions

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Design, equipment, installation and launch of RAS fish farms for sturgeon, trout, African catfish and other fish species.

Offices and details
Sway LLPBIN 160840020113Astana: Turan Avenue, 16, office 8Russia: Varshavskoe shosse, 33, building 1, Moscow
© 2026 Aquafarmer · Turnkey RAS fish farmsThe numbers on the page are approximate. Exact indicators are calculated individually.
Aquafarmer project photo