The Black Mahseer is a large freshwater carp introduced to Sri Lanka from India, although it has become well established in several river systems and reservoirs across the island. It is commonly found in clear, fast-flowing rivers, deep pools, and large reservoirs with rocky or gravelly bottoms. This powerful fish prefers well-oxygenated waters and is especially associated with upland and foothill river habitats. The Black Mahseer is a strong swimmer and an active omnivore, feeding on aquatic insects, crustaceans, small fish, algae, fruits, seeds, and other plant material. Juveniles often form small groups, while larger adults are more solitary or occur in loose aggregations. Due to its impressive size and fighting ability, it is highly regarded as a sport fish and is also valued as a food fish. Although widely known in Sri Lanka as ලෙහෙල්ලා, the Black Mahseer is not native to the island. It was introduced for fisheries and recreational angling and has since established breeding populations in several freshwater systems. As a large introduced species, it may compete with native fishes for food and habitat, making its ecological impact an important consideration in freshwater conservation.