Xingyun Lake Yunnan loach

Where they come from

Yunnanilus analis is one of those little Chinese hillstream-style loaches that comes from Yunnan. Think cool, well-oxygenated water with lots of rocks, gravel, and current. They are not a big river bruiser kind of fish - more like a small, bottom-hugging grazer that likes clean water and steady conditions.

Setting up their tank

If you try to keep these like generic community loaches in a warm, low-flow planted tank, they usually fade out over time. The best results I have had were basically a small riverbed setup: strong filtration, lots of oxygen, and a layout that gives them places to wedge themselves and forage.

• Tank size: I would not do less than 20 gallons long for a group. More footprint beats more height.
• Flow and oxygen: a canister or strong HOB plus a powerhead works great. Add an airstone if your surface is not really moving.
• Substrate: smooth gravel and mixed rounded stones. Skip sharp stuff - they spend their whole life on the bottom.
• Hardscape: piles of river rocks, cobbles, and a few pieces of wood for breaks in the current. They love seams where fast water meets calm water.
• Plants: optional. If you use them, pick hardy ones (Anubias, Bolbitis, Java fern) tied to rock/wood. Most delicate stems get battered in flow.

Temperature-wise, I have done best keeping them on the cooler side for a tropical tank. Room-temp setups often work better than heated ones. If you keep them warm year-round, they seem to burn out faster and get touchier about oxygen.

What to feed them

They are constant pickers. In my tanks they spent the whole day grazing rocks and substrate, then really came alive at feeding time. The trick is to feed like you would for small bottom insect-eaters, not like you would for big loaches that smash wafers.

• Staples: small sinking micro pellets, crushed high-quality wafers, and fine granules that actually reach the bottom
• Frozen: cyclops, daphnia, baby brine shrimp, chopped bloodworms (not huge chunks)
• Live (if you can): grindal worms, microworms, small blackworms in moderation
• Grazing food: algae wafers are fine, but do not expect them to live on algae alone

If you keep them with faster midwater fish, use a feeding tube or drop food right into their favorite rock piles so they get their share. They are quick once they commit, but they do not like racing in open water.

How they behave and who they get along with

They are generally peaceful, a bit shy at first, and way more confident in a group. You will see little squabbles over the best rock or crevice, but it is more posturing and short chases than real damage. Once settled, they are fun to watch because they use every inch of the bottom and hardscape.

• Best kept in groups: I would start with 6+ if your tank footprint allows it
• Good tankmates: small, calm fish that like cooler, clean water and flow (think danios from cooler water, white cloud mountain minnows, some small barbs), and other peaceful bottom fish that will not bulldoze them
• Avoid: big boisterous loaches, aggressive barbs, large gouramis/cichlids, and anything that wants warm, still water

They also do better with plenty of broken sight lines. If the whole bottom is one open flat, the boldest fish tends to claim it and the others hide. Rock piles and little caves spread them out.

Breeding tips

Breeding Yunnanilus in the home aquarium is possible, but it is not as straightforward as dropping in a spawning mop. Most hobbyist successes I have seen (and my own best attempts) looked like they happened after a seasonal-style change: a stretch of heavier feeding, then a cool water change and a bump in flow.

• Conditioning: feed heavier for a couple weeks with frozen/live foods
• Trigger: a few larger cool water changes over several days, plus extra current and oxygen
• Spawning sites: fine-leaved plants, moss, or rock piles with tight gaps where eggs can fall out of reach
• Egg/fry safety: adults will snack if they find them, so a separate breeding tank or an egg trap approach helps

Common problems to watch for

Most issues with these come back to three things: too warm, not enough oxygen/flow, or a tank that is not stable. They can look fine for a month or two and then just start dropping if the setup is off.

• Slow wasting and hiding: often chronic stress from warm water, low oxygen, or long-term nitrate buildup
• Gasping or clustering at the outlet: oxygen problem first, temperature problem second
• Sunken belly: not getting enough food (or getting outcompeted), internal parasites in wild fish, or both
• Scrapes/barbel wear: sharp substrate, dirty substrate, or fish constantly digging through crud for food
• Ich and other parasites after purchase: common with wild-caught fish, especially if they are shipped warm and crowded

My biggest quality-of-life tip: keep your maintenance boring and consistent. Regular water changes, keep the flow strong, and clean the filter in old tank water so you do not crash your biofilter. These fish reward steady hands, and they punish shortcuts.