Schistura is a large genus of stone loaches in the family Nemacheilidae, small elongate bottom-dwelling fish built for life in fast, oxygen-rich hill streams and rocky rivers across South and Southeast Asia. The atlas currently covers 233 species, drawn from across Laos, India, Thailand, China, Vietnam, Myanmar, Pakistan and Cambodia, a spread that reflects the genus's real center of diversity in streams draining the eastern Himalaya and the hill country of Indochina. Adults run from barely 1 in up to about 5.5 in, and most species share the loach body plan: a cylindrical, faintly barred or mottled body, a flattened underside, and small barbels around a downturned mouth used to pick invertebrates off stones and gravel. Many species are restricted to a single stream system, which is part of why so many remain poorly studied.
Few Schistura reach the general aquarium trade, and most that do are kept by specialists rather than casual hobbyists, since these are current-loving fish that want cool, well-oxygenated, flowing water rather than a still community tank. A handful have earned aquarium names from their markings: the Sumo loach (Schistura balteata), the Creek loach (S. beavani), and the striking black-and-yellow Batman loach (S. chrysicristinae) among them. Conservation data for the genus is thin. The IUCN tally leans heavily on Data Deficient and Not Evaluated species (63 and 78 respectively in the atlas), with smaller numbers formally assessed as threatened, a gap typical of range-restricted stream fish that are hard to survey.
Schistura has absorbed a steady stream of newly described species over the past few decades as ichthyologists have surveyed previously unstudied streams in Laos, Vietnam and Myanmar, and the genus is likely to keep growing as more remote drainages are sampled. Because so many species are separated by subtle differences in fin ray counts, body markings and barbel length, confident identification usually depends on close comparison with the original description rather than a photograph alone.