South Caucasian gudgeon

Where they come from

South Caucasian gudgeons live in the Kura and Aras river systems across the South Caucasus and nearby regions. Think clear, cool rivers with steady current, gravelly riffles, and quieter runs between them. They spend their time right on the bottom, sifting sand and pebbles for tiny snacks.

Setting up their tank

Give them a long tank and good flow. A 30 to 36 inch tank works for a small group, but more length is always nicer. They appreciate clean, oxygen-rich water and a bottom they can rummage through without tearing up their barbels.

• Substrate: fine sand or very small rounded gravel. Add smooth river stones and cobbles.
• Flow and oxygen: strong filtration and powerheads. Aim for 8-12x turnover with plenty of surface agitation.
• Water: 14-22 C, pH 6.8-8.0, moderate hardness. Keep nitrates low with weekly water changes.
• Aquascape: build a couple of rock piles to break line of sight and create resting eddies. Leave open runs for cruising.
• Plants: optional. If you want greenery, use hardy, attached plants like Anubias or Java fern on rocks so they do not uproot.

What to feed them

In the wild they pick at insect larvae, worms, tiny crustaceans, and whatever micro-life they sift from the substrate. In a tank, they switch to prepared foods if you keep it small and sinking.

• Staples: high-quality sinking micro-pellets, crushed wafers, and small soft pellets.
• Frozen and live: bloodworms, blackworms, daphnia, cyclops, chopped earthworms. Rotate for variety.
• Extras: Repashy-style gel foods pressed into pebbles so they can rasp naturally.

How they behave and who they get along with

They are peaceful bottom fish with short bursts of energy in the flow. In a group of 6 or more, they are confident and spend more time out in the open. Males may posture a bit, but it is mostly harmless if the tank has space and cover.

• Good tankmates: white cloud mountain minnows, small dace or minnows that like cool water and current, hillstream loaches, small stone loaches, other non-nippy river cyprinids.
• Avoid: large or aggressive fish, warmwater tropicals, and super-fast midwater fish that hoover up every crumb before food sinks.

Breeding tips

They are seasonal spawners that scatter eggs over gravel in spring. It is doable at home if you can give them a cool period and then a gentle warm-up with extra flow.

• Condition a group with heavy live and frozen foods for a few weeks.
• Winter rest: hold them at 10-12 C for 4-6 weeks with short photoperiod.
• Spring cue: raise to 16-18 C, extend day length, and boost current.
• Use a bed of mixed pea gravel over a mesh so eggs can drop out of reach.
• If they spawn, remove adults. Eggs usually hatch in 3-6 days depending on temperature.
• Start fry on paramecium or rotifers, then microworms and newly hatched brine shrimp.

Common problems to watch for

• Heat and low oxygen: panting at the surface, flashing in the flow. Add air, drop temperature, and increase surface agitation.
• Barbel damage: sharp gravel or rough rocks scrape them up and invite infection. Stick to smooth substrates and keep the bottom clean.
• Dead spots: if mulm settles in quiet corners, you will see lethargy and fin issues. Reposition flow or add a small powerhead.
• Wild-caught hitchhikers: flukes and worms are common. Quarantine new fish for 4 weeks and treat if needed.
• Food competition: midwater fish can out-speed them. Target feed with tongs or use a feeding tile so the gudgeons get their share.