Homalopteroides is a genus of hillstream loaches (family Balitoridae) built for life in fast, well-oxygenated Southeast Asian hill streams — the atlas records the genus across Thailand, Cambodia, Laos, Vietnam, Myanmar, India, Malaysia and Indonesia. Like the rest of the hillstream-loach group, its members have a flattened, torpedo-shaped body and broadly paired pectoral and pelvic fins that spread into a sucker-like disc, letting the fish grip smooth rock in strong current while grazing algae and biofilm off the substrate. The atlas covers 9 species, spanning roughly 1–4 in.
The genus sits at the edge of mainstream fishkeeping rather than in it — hillstream loaches in general appeal to a dedicated niche of stream- and riffle-tank builders rather than to community aquarists, and species such as Homalopteroides tweediei (Tweedie's hillstream loach) and H. weberi (Weber's hillstream loach) turn up in that circle. Care follows the group pattern: cool to moderate water, heavy current and high dissolved oxygen — often from powerheads or a raised outflow — a bare or gravel-and-rock substrate, and a diet built around algae with occasional sinking foods. Conservation data are thin: of the nine species the atlas tracks, four are Least Concern, three are Data Deficient, one has not yet been formally evaluated, and one is Vulnerable, a reminder that clear hill-stream habitat is easily degraded by siltation, deforestation and small-scale damming.