Freshwater fish with regularly ossified skeleton. Long body, latterly flattened with no scales. Head relatively small. Mouth broad with small sharp teeth on jaw, vomerine and palatal bones. Eyes relatively large. Two pairs of barbels, upper shorter than the lower. Fins dark grey or black. Two dorsal fins, the first one larger than the second one. Young fish have black stripe along lateral line and another long black stripe below lateral line; large adults uniformly grey but sometimes with greenish tint and sides silvery. Dark stripe on middle of anal fin; dark stripe in each caudal lobe.
- Area 4: Asia - Inland waters