Spindle Yunnan loach

Where they come from

Spindle Yunnan loaches (Yunnanilus elakatis) come from Yunnan in southwest China. Think cool, clear water, lots of rounded stones, leaf litter, and steady flow rather than warm, slow, weedy ditches.

That background explains most of their quirks in the aquarium: they like oxygen-rich water, they spend a lot of time on and around the bottom, and they get bolder when they have cover and a group.

Setting up their tank

Give them floor space more than height. A 20 long style footprint works really well for a small group, and bigger always makes them easier. They are not huge fish, but they use every inch of bottom.

• Substrate: sand or very smooth fine gravel (they sift and scoot along the bottom)
• Hardscape: rounded river stones, small cobbles, and a few pieces of wood to break up sight lines
• Cover: leaf litter, clumps of moss, and plants around the edges (they like pockets to retreat into)
• Flow and oxygen: a sponge filter plus a small powerhead, or a HOB aimed along the back to create a gentle current
• Lighting: moderate; floaters or taller plants help them feel less exposed

Water wise, they do best on the cooler side for a "nano" fish. Room temp is usually fine, and they generally appreciate stability more than chasing a perfect number. I avoid running them hot - warmer water holds less oxygen and they get noticeably less active.

What to feed them

These loaches are little micro-predators and pickers. In my tanks they spend the day hunting through biofilm and mulm, then go nuts for small meaty foods. They can learn prepared foods, but they look best (and act most natural) with a mix.

• Staples: small sinking pellets, micro wafers, and fine granules that reach the bottom
• Frozen: cyclops, daphnia, baby brine shrimp, chopped bloodworms (not too much), mysis if you chop it
• Live (great for conditioning): baby brine shrimp, microworms, grindal worms, live daphnia if you have it
• Occasional: repashy-style gel food pressed into crevices so they can graze

If you keep them with faster midwater fish, make sure some food actually reaches the bottom. I like using a turkey baster to squirt thawed food right into the rock piles.

How they behave and who they get along with

They are peaceful, a bit skittish at first, and way more interesting in a group. You will see little pecking-order stuff (short chases, posturing), but it is usually harmless if the tank has lots of broken sight lines and multiple hiding spots.

• Good tankmates: small rasboras, danios that are not too boisterous, hillstream-type peaceful bottom fish (in larger tanks), small peaceful tetras, cherry shrimp (adults usually fine)
• Use caution with: other bottom dwellers in tight footprints (they can get outcompeted for food), tiny shrimp shrimplets (may get picked off), very active barbs
• Avoid: aggressive cichlids, big gouramis, anything that treats the bottom like its territory, and large predatory fish

I also recommend a tight lid. They are not classic jumpers like some danios, but startled loaches do weird things, and you do not want to find one dried behind the stand.

Breeding tips

They can spawn in the aquarium, but it is not a guaranteed "easy breeder" like livebearers. The best luck usually comes from a well-fed group in a mature tank with lots of fine plants or moss for eggs to disappear into.

• Start with a group (6+ if you can) so you have both sexes and natural behavior
• Condition with live/frozen foods for a couple weeks
• Provide spawning spots: dense java moss, subwassertang, or a mesh mop near the bottom
• A cooler water change can sometimes trigger activity, especially if your tank runs warm

For first foods, think tiny: infusoria, vinegar eels, microworms, then baby brine shrimp once they can take it. A mature, slightly "dirty" (in a good way) grow-out tank helps because there is always something for them to graze.

Common problems to watch for

• Hiding nonstop: usually too bright, not enough cover, kept solo, or stressed by aggressive tankmates
• Getting skinny: food not reaching the bottom, or they are being outcompeted by faster fish
• Rapid breathing or hanging in the flow: low oxygen, clogged filter, warm water, or organics trapped under rocks
• Mystery losses after purchase: sensitivity to swings during acclimation, or parasites from new stock

The biggest quality-of-life upgrade for them is steady, clean water with lots of oxygen and a mature tank. If you keep up with reasonable water changes, avoid overfeeding, and give them rocks, shade, and a group, they are surprisingly hardy once settled.