Tor, the mahseers, is a genus of large freshwater cyprinids native to fast-flowing rivers of South and Southeast Asia, with atlas records spanning India, Bangladesh, Myanmar, China, Laos, Thailand, Malaysia, and Indonesia. Size in the atlas runs from a modest 2 in for the smallest species up to reports of specimens approaching 2.75 metres for the largest mahseers, among the biggest cyprinids in the world. The genus is defined by large scales, a thick-lipped, sub-terminal mouth suited to feeding on algae, fallen fruit, and invertebrates in strong current, and, in several species, prominent barbels.
Mahseers are legendary game fish across South Asia - the golden mahseer (T. putitora) and Deccan mahseer (T. khudree) in particular are celebrated by anglers for their strength in fast Himalayan and peninsular Indian rivers, and some populations carry deep cultural or religious significance, protected in temple tanks in parts of India. The genus is far more a subject of conservation, fisheries, and angling interest than home aquarium keeping, since adult mahseer are simply too large for a typical tank. Multiple species in the atlas are Endangered, Critically Endangered, or Data Deficient, reflecting pressure from damming, overfishing, and habitat degradation across the group's range.