Oreonectes is a genus of small stream loaches found in southern China, Hong Kong, and Vietnam, notable for including several fully cave-adapted species alongside more typical surface-dwelling stream forms. The cave species, such as Oreonectes anophthalmus (blind cave loach), live in karst cave systems in Guangxi and show the classic troglomorphic package — no functional eyes and little to no body pigment — a pattern that has evolved independently in several unrelated cave-fish lineages worldwide. The surface species instead occupy fast, clear hill streams typical of the wider loach family, with the same elongate, cylindrical body plan. The atlas covers 18 species, adult size roughly 1.5–4 in.
Oreonectes is essentially a scientific-interest genus rather than a hobby staple; the blind cave species occasionally reach specialist keepers fascinated by cave-fish biology, but neither the eyeless nor the sighted species are common in general fish stores. Cave-restricted populations like these are typically narrow-range by nature, confined to a single cave system or karst aquifer, which makes them inherently vulnerable to local water-table changes or pollution even when formal assessment is lacking. That pattern fits the atlas's IUCN tally, which is mostly Not Evaluated with a scatter of Data Deficient and Least Concern species and one Vulnerable species, rather than a genus with broad, well-documented protection.