Barbonymus is a genus of medium to large barbs in the carp family Cyprinidae, native to the rivers of Sundaic and mainland Southeast Asia — the atlas's countries include Malaysia, Indonesia, Cambodia, Thailand, Vietnam, Laos, Brunei, and Singapore. These are deep-bodied, laterally compressed barbs, several growing to 12 in or more, with a downturned mouth and barbels suited to foraging over sand and mud substrate in lowland rivers, floodplains, and slow backwaters; many species also tolerate the murkier, warmer conditions of disturbed or seasonally flooded habitat.
The genus supplies two of the aquarium trade's classic large schooling barbs: the tinfoil barb (Barbonymus schwanefeldii) and the red-tailed tinfoil (B. altus), both fast-growing, silver-bodied fish that need a spacious tank and reward keepers with an active, shoaling display. The silver barb (B. gonionotus) matters more as food than as an ornamental — it is one of Southeast Asia's most widely farmed freshwater fish. Most Barbonymus populations remain Least Concern, though the atlas flags one species as Critically Endangered, a reminder that even a widespread, commercially important genus can carry a localized population under serious pressure.