Homatula is a genus of nemacheilid loaches — the same family as the familiar stone and dwarf loaches of the aquarium trade — confined to China. Most of its species were carved out of the older, unwieldy genus Triplophysa in taxonomic revisions over the past two decades and are tied to the karst limestone country of Yunnan, Guizhou and neighbouring provinces, where cave systems and spring-fed streams riddle the landscape. The genus shares the family's slender, faintly barred body, downturned mouth and three pairs of barbels for probing gravel and silt, and, as in many karst nemacheilids from this region, a few relatives show the reduced eyes and pale colouring associated with life in caves and groundwater.
The atlas currently covers 22 Homatula species, nearly all recorded from a single country, and the genus is a scientific rather than a hobby one: only a couple of names, such as H. potanini (the Chinese elongated zebra loach) and H. variegata (the variegated stone loach), turn up under trade names, and even those are seen far more often in ichthyological surveys than in shops. The IUCN picture reflects how recently much of the genus was described — the majority of species are Not Evaluated, with one classed Endangered and two Vulnerable, so conservation status here is still mostly an open question rather than a settled one.