Highbody longnose gudgeon

Where they come from

Highbody longnose gudgeons are small river cyprinids from Taiwan and nearby East Asian drainages. Think clear, fast, shallow streams with sand and pebbles, lots of oxygen, and seasonal shifts in temperature. They spend their time nosing through the substrate for tiny snacks.

Setting up their tank

If you give them current and clean water, they settle in fast. A 30-40 gallon long (or any 90 cm/3 ft tank) works for a group of 6-8. They like floor space more than height.

• Substrate: fine sand or very small rounded gravel so they can sift without scraping their snouts.
• Flow: aim a powerhead or canister return along the length of the tank. I like a spray bar plus a small powerhead. Surface movement = oxygen.
• Hardscape: smooth river stones, cobbles, and a few wood pieces. Make broken sight lines so subdominant fish can duck out.
• Plants: optional. Go with hardy, attached types like Anubias, Bolbitis, or moss on rocks. They handle flow better than rooted stems.
• Filtration: oversized canister or HOB with pre-filter sponges so nobody gets pinned to the intake.
• Lid: tight-fitting. They rocket off if spooked. I tape the back gaps around cables.

Maintenance is simple but regular: 30-50% weekly water changes, clean the pre-filter sponge often, and vacuum lightly so you do not strip all the biofilm from the stones.

What to feed them

They are little sifters. Mine ignore most flakes and go for anything that sinks and looks alive.

• Staples: small sinking pellets (nano-sized), quality wafers, and gel foods spread thin on a rock.
• Protein: frozen or live foods a few times a week - daphnia, brine shrimp, bloodworms, blackworms. Rinse frozen foods.
• Grazing: they pick at biofilm and microalgae on stones. Sun a few rocks in a tub outside and rotate them in if you want to spoil them.
• Veg boost: tiny bits of blanched spinach or zucchini now and then, mostly for variety.

How they behave and who they get along with

Peaceful, busy, and very into their own business. In a group they do short chases to sort out pecking order, then go back to sifting. Solo fish get jumpy and hide more.

• Group size: 6+ spreads out any sparring. Aim higher if your tank allows.
• Good tankmates: current-loving, non-nippy species like danios, smaller barbs (cool-tolerant ones), hillstream loaches, white cloud mountain minnows, Rhinogobius-type gobies.
• Avoid: big cichlids, anything that snacks on small bottom fish, and slow long-finned fish that hate flow. Very warm-water fish are a bad match.

Breeding tips

They are likely seasonal scatter spawners over gravel in brisk water. It is doable but not a beginner project. I had best results after a cool winter period and a spring warm-up with heavy feeding.

• Conditioning: cool them to around 18-19 C for a few weeks, then nudge up to 22-23 C and increase flow and water changes.
• Spawning site: a tray of smooth pebbles or marbles so eggs drop out of reach. Strong, well-oxygenated current right over it.
• Sexing: females get rounder; males may show small breeding tubercles and posture more.
• Post-spawn: adults offer no care and may eat eggs. Pull the tray or move adults when you see vigorous chasing.
• Rearing: eggs hatch in 2-4 days depending on temp. Start fry on infusoria/rotifers, then baby brine shrimp. Keep flow gentle but oxygen high. Sponge filter only in the fry tank.

Common problems to watch for

• Low oxygen and heat: the combo makes them gasp and go off food. Add surface agitation and cool the tank a bit.
• Injured snouts/barbels: usually from sharp gravel. Swap to sand or smoother pebbles.
• Weight loss: often from offering only flake. They need sinking foods they can actually find in current.
• Parasites on new arrivals: many are wild-caught. Quarantine 3-4 weeks. Observe for flashing, stringy poop, or hollow bellies.
• Ammonia spikes near the bottom: they live on the floor where waste collects. Keep up on water changes and do not overpack the substrate with gunk.
• Jumping: startled fish clear lids. Cover every gap, even around filter pipes.