The Spotback Loach is a small freshwater fish endemic to Sri Lanka, found in clear, fast-flowing streams and rivers of the island’s wet zone and central highlands. It inhabits well-oxygenated waters with rocky or gravelly substrates, where it shelters beneath stones and among crevices to avoid strong currents and predators. This bottom-dwelling species is highly adapted to life in flowing waters, using its streamlined body and broad fins to maintain its position on the stream bed. It is generally solitary or found in small groups and feeds on aquatic insect larvae, small crustaceans, worms, algae, and other tiny organisms collected from the riverbed. The distinctive dark marking on its back gives rise to its common name, the Spotback Loach. As a species found only in Sri Lanka, the Spotback Loach is an important part of the island’s unique freshwater biodiversity. It is sensitive to water pollution, habitat degradation, and changes to natural stream flow, making the protection of Sri Lanka’s forest streams and river catchments essential for its conservation.