Vanmanenia loach

Where they come from

Vanmanenia striata is a hillstream loach from fast, shallow streams in southern China and nearby parts of northern Vietnam. Think clear water blasting over smooth stones, with a ton of oxygen and a steady buffet of algae and micro-life growing on the rocks. Their flat bodies and wide fins are built to hug those boulders like suction cups.

Setting up their tank

If you give them current and oxygen, you are 80% of the way there. A 20-long is the smallest footprint I would use for a small group, but 30 to 40 gallons with more floor space is nicer. Aim for cool, clean, fast water.

• Flow and O2: Strong powerheads or a river-manifold setup. Target 10-20x tank turnover and lots of surface agitation.
• Temp: 68-74 F (20-23 C). They sulk over 76 F and suffer in heat waves.
• Water: pH 6.5-7.5, soft to moderate hardness. Keep nitrates under 20 ppm.
• Substrate: Sand or fine gravel with rounded river stones and cobbles. Smooth surfaces grow the best biofilm.
• Lighting: Moderate to bright to grow algae on the rocks. I let a few stones sit in a sunny window to seed green algae, then rotate them in.
• Cover: Tight lid. They can wriggle up the glass in strong flow.
• Mature filtration: Sponge pre-filters on inlets so they are not pinballed around.

What to feed them

They are biofilm and algae grazers first, scavengers second. Mine spend most of the day rasping stones. You still need to feed them, but the tank itself should be part of the menu.

• Repashy Soilent Green or Super Green smeared on stones and let set
• Quality algae wafers and spirulina flakes (sink them into the current)
• Blanched veggies: zucchini coins, spinach, green beans
• Frozen foods as extras: daphnia, cyclops, baby brine; bloodworms only as an occasional treat
• Powdered foods for aufwuchs-grazers dusted over rocks

How they behave and who they get along with

They are busy little rock surfers. Expect short chases and body-pressing matches between males, but I rarely see damage if there are multiple stones and sight breaks. They mostly ignore midwater fish.

• Best kept: In a group of 4-6+ to spread out squabbles.
• Good tankmates: White cloud mountain minnows, danios, smaller barbs that like current, small hillstream loaches (Sewellia, Gastromyzon), shrimp that can handle flow.
• Avoid: Big or pushy fish, slow fancy fins, warm-water species, and anything that outcompetes them on the bottom (large plecos).

Breeding tips

It is uncommon but not impossible. They are likely egg scatterers that tuck eggs under stones in strong flow. I have not raised a batch to adulthood, but here is what has pushed activity for me and others:

• Condition with lots of green foods and small live/frozen fare for a few weeks.
• Give them a carpet of rounded pebbles, a few flat slate pieces, and tight gaps under stones.
• Run heavy current and high oxygen. Keep temps around 70 F.
• Try a rainy-season cue: several cool water changes and a small bump in flow.
• If you suspect eggs, move adults or lift stones into a fry box with matching flow.
• Fry are tiny and need biofilm, infusoria, and powdered algae foods in high oxygen.

Common problems to watch for

• Starvation on arrival: Many arrive thin and unfamiliar with prepared foods. Quarantine and offer constant access to algae-smeared stones.
• Heat and low oxygen: Hot rooms can crash them fast. Add fans, airstones, and big surface ripple during heat waves.
• Internal parasites: Skinny despite eating. I treat in quarantine with a loach-safe dewormer regimen.
• Bacterial scrapes: They wedge under rocks; keep stones smooth and water clean to avoid infections.
• Competition: Midwater pigs will out-eat them. Target feed into the flow and add extra feeding spots.
• Medication sensitivity: Like other loaches, they are sensitive to some dyes and copper. If you must medicate, start at a reduced dose and boost aeration.