The Longfin Eel is a freshwater and migratory eel species native to Sri Lanka and widely distributed across South Asia and the Indo-Pacific region. In Sri Lanka, it is found in rivers, streams, reservoirs, wetlands, and coastal freshwater habitats. Like other freshwater eels, it has a complex life cycle, migrating to the ocean for breeding while juveniles return to freshwater systems where they grow into adults. This elongated and secretive fish is mainly nocturnal, spending the daytime hidden among rocks, muddy substrates, submerged roots, and aquatic vegetation. It is well adapted to different freshwater conditions and can move between connected waterways. The Longfin Eel is a carnivorous predator that feeds on small fish, aquatic insects, worms, crustaceans, and other small aquatic animals. The Longfin Eel is an important native predator in Sri Lanka’s freshwater ecosystems and contributes to maintaining balance within aquatic food chains. Its ability to migrate between freshwater and marine environments makes it a unique component of Sri Lanka’s aquatic biodiversity. Conservation of river connectivity, clean water habitats, and natural wetlands is essential for protecting this species.