Sturgeon

Oxygen shortage / stopped swimming

SignsSnout out at the surface, constantly rubbing the nose on the wall, rolling over and sinking to the bottom, rapid gill movement. Spikes sharply at high water temperatures

PreventionKeep dissolved oxygen high at all times with two independent air pumps. Tank with no corners; keep water below 25°C in summer

Heat stress

SignsAbove 26°C: loss of appetite, sluggishness, swimming tilted to one side. Above 28°C, death within hours

PreventionKeep around 20°C year-round with a chiller or fan. Install two thermometers and check twice a day in summer

Ammonia / nitrite poisoning

SignsDark red gills, rapid breathing near the surface, increased mucus making the skin look cloudy white. Having no scales, it is affected quickly

PreventionHeavy feeders produce a lot of waste: strong filtration and a 1/3 water change 1–2 times a week. Test with strips every week

Water mold (fungus)

SignsWhite cotton-like growth on wounds on the snout or scutes. Starts from wall-collision wounds or net abrasions

PreventionBuild a tank that cannot cause wounds. Move the fish by hand or in a container, not a net. If you find a wound, improve water quality and see the vet early

Aeromonas infection

SignsRed hemorrhagic spots on the belly or between the scutes, swollen belly, bulging eyes, redness at the fin bases

PreventionTriggered by rising temperature and poor water quality. Change water more often in summer and remove leftover food the same day

Snout and scute damage

SignsSnout worn white and raw, missing barbels, chipped scutes. Happens when the fish keeps hitting the walls of a rectangular tank

PreventionRound tank, or round off the corners. No driftwood or sharp rocks. Prevent jumping out with a lid

Getting wedged in a gap

PreventionIt cannot back up, so leave no gaps between equipment and walls, and no plants or decorations. Enclose heaters in a guard

First aidDo not pull it out backward by the head; remove the object trapping it and let it move forward on its own. Direct current at the gills so they can work; see the vet if there are wounds

Jumping out / falling

PreventionIt jumps when startled. Cover the whole tank with a heavy lid and keep the water level at least 10 cm below the rim

First aidPick it up with wet hands and return it to the tank. Pour water over any dried skin and support it in front of the current until it swims. Chipped scutes or bleeding: see the vet

Snout abrasion

PreventionHappens when it keeps swimming along the walls of a tank with corners. Use a round tank, or place pipes in the corners to round them off

First aidKeep the water clean; if the raw area spreads or white fungus grows, see the vet. Lost barbels affect foraging, so help by hand-feeding

Net abrasion

PreventionScaleless skin is damaged by net friction. Move the fish in a large container, or scoop it in a bag instead of a dip net

First aidMucus thickens and turns white over the abrasion. Keep the water clean; if it becomes red and swollen or fungus grows, see the vet within a few days

Nontuberculous mycobacterial infection

RouteThrough cuts on hands that touch tank water or the fish

PreventionWear waterproof gloves if you have cuts on your hands. Wash hands with soap after tank work. A swelling that does not heal: see a dermatologist

Aeromonas wound infection

RouteWater entering a cut made by the sharp edge of a scute

PreventionWear thick gloves when handling the fish. Rinse cuts under running water and disinfect; see a doctor if they swell

Edwardsiellosis

RouteTank water or fish feces entering a wound or the mouth

PreventionWash hands after water changes. Never start a siphon by mouth. People with weak immune systems should avoid tank work

Salmonellosis

RouteEating with hands that touched tank water or equipment

PreventionDo not wash equipment in the kitchen. Drain water outdoors or in the bathroom, not the kitchen sink. Wash hands after tank work

Food

• Sinking sturgeon pellets as the staple, 2–3 times a day
• Juveniles: small amounts 3–4 times a day; adults: 1–2 times a day
• Frozen bloodworms and shrimp as supplements. It cannot eat floating food

Water

• Aim for dissolved oxygen of 7 mg/L or more with strong aeration
• Slightly alkaline to neutral; change water 1–2 times a week so nitrate does not build up

Toys & play

• No toys needed. Create a current to swim against with a flow pump
• Tame it by hand-feeding (it may suck on your finger but does not bite)
• Foraging on the bottom is stimulation in itself

Nest, bed & hideout

• No hiding place needed; in fact it is a trapping hazard, so do not add one
• Just a shade board over the tank to create some shadow

Bedding & litter

• No substrate (bare tank) is safest and easiest to clean
• If you must, a thin layer of fine sand with no sharp edges
• Never gravel: it is swallowed and blocks the intestine

Cage / housing material

A round FRP or polyethylene tank is ideal. For glass, round off the corners

Size & space

Juveniles: 90 cm or more; adults: 1.5–2 m in diameter, 1,000 L or more

Layout

• Round, or with rounded corners, so the fish can circle along the walls
• Press equipment flush against the walls, leaving zero gaps
• A flow pump to create current and several air stones

Placement notes

• A spot out of direct sunlight that can be kept below 25°C in summer
• 1,000 L weighs over 1 t. Check floor load capacity; keep it on the ground floor or outdoors

Exercise, free-roam & walks

• No walks needed. Constant room to swim and a current are its exercise
• If it spends more time with its snout near the surface, act
• During a power outage, keep it swimming with a battery-powered air pump

Temperature & humidity

Temperature15–22°C is ideal. Above 25°C is dangerous; 28°C is fatal

HumidityNot applicable as it lives in water. Watch for condensation on the lid near electrical equipment

Summer & winter

• Summer: keep below 25°C with a tank chiller, fan and shading
• Winter: tolerates cold well, no heating needed. Just prevent freezing

Nail trimming

No nail trimming. Instead, check the snout and scutes daily for wounds and remove any corners or equipment that cause them

Brushing, skin & coat care

Do not touch the body; it has no scales and the mucus protects the skin. Move it in a bag or container and avoid nets

Other care

Clean the filter and air stones weekly to keep oxygen supply up. Make checking the thermometer and dissolved oxygen a habit

Protection from predators

• Outdoors, net the whole tank against herons, crows and raccoons
• Weight the lid down so cats cannot open it
• Kept with other fish, it loses bottom food to them and gets thin

Foreign-body ingestion

It sucks up gravel and dropped parts along with food. Use a bare tank and retrieve dropped equipment at once. Loss of appetite with a swollen belly: see the vet

Being stepped on

Stepping on a fish flopping on the floor. If you notice it has jumped out, turn on the light and check your footing, then lift it with wet hands

Getting pinched

It gets wedged head-first in gaps between the wall and heaters, pumps or pipes, cannot back out and suffocates. Fix equipment flush against the wall with no gaps

Falls

Jumping out of the tank can be fatal in minutes. Cover the whole tank with a heavy lid and keep the water level at least 10 cm below the rim

Escape

Outdoor tanks overflow in heavy rain and the fish is washed out. In rivers it becomes an invasive species problem, and release is prohibited. Put mesh over drains

Safe release procedure

1. It has no teeth and only sucks, so there is almost no pain
2. Relax your hand and wait underwater for the fish to spit it out
3. If it does not let go, direct a gentle stream of water at the side of its mouth
4. If a scute cuts you, return the fish first, then rinse under running water

After the release

Rinse finger cuts under running water and disinfect. If swelling or redness spreads, see a dermatologist. Check the fish's mouth for injury

What to tell the vet & what to bring

Water temperature, dissolved oxygen, ammonia and nitrite readings, tank volume and fish length, video of symptoms, date of the last water change

Checking consciousness, breathing & heartbeat

• Watch the gill covers open and close. Regular movement while swimming is normal
• Does it flee when you bring your hand close? Do the barbels move?
• Is the body level? Rolled over or upside down means critical

Stopping bleeding

• Fish bleeding is hard to stop underwater. Keep the water clean
• Do not touch the wound; if the water is cloudy, change it to prevent infection
• If bleeding continues or the wound is deep, transport it to the vet

Transport

• Carry it in a large bag or cooler box with water and oxygen, kept dark
• In summer use ice packs to prevent the water warming; shape the bag round so it has no corners