Yunnanilus cruciatus is a small, lively nemacheilid loach from the rivers and streams of Yunnan province in southwestern China. Its common and scientific name reference the distinctive cross-shaped (cruciform) dorsal marking visible in well-conditioned individuals — a dark saddle-mark intersected by a lateral stripe, creating a distinctive X or cross pattern. The species is relatively small and active, darting energetically through the water column in groups.
In the aquarium, Y. cruciatus requires the cool, well-oxygenated conditions typical of upland Chinese stream fish. It is somewhat more water-column active than strict hillstream loaches and appreciates open swimming areas alongside rocky shelter. Its small size makes it suitable for 60-litre tanks when kept in groups of six or more, making it accessible to keepers with limited space who wish to keep hillstream-adapted fish.
This species is more tolerant of moderate current than extreme-flow hillstream loaches and can be maintained in a standard cool-water aquarium with good filtration and surface agitation rather than requiring a dedicated hillstream powerhead setup. However, water temperature must remain firmly in the cool range — above 22 °C will cause chronic stress.
