Syncrossus is a genus of banded loaches in family Botiidae, native to fast-flowing rivers and streams across Southeast Asia, including Thailand, Malaysia, Laos, Myanmar, Brunei, Cambodia, Indonesia, and Vietnam. Members share the family's diagonal or vertical dark banding and the small erectile subocular spine typical of botiid loaches, and most are bottom-oriented fish tied to well-oxygenated, current-swept water.
Several species are well known in the aquarium trade: the tiger loach (S. helodes), the polka-dot botia (S. hymenophysa), and the reverse clown loach (S. reversus) are all kept by loach specialists for their bold patterning and active, social behavior. The genus spans an unusually wide size range for the atlas - roughly 2.5–12 in - so tank and social requirements differ a lot by species. Two of the five atlas species are assessed Near Threatened, a reminder that Southeast Asian river habitats face ongoing pressure from damming and land-use change.