Clarias

Clarias is a genus of freshwater catfishes in the family Clariidae, commonly referred to as airbreathing or walking catfish. The genus encompasses numerous species native to Africa and Asia, with some species introduced to other regions. The best-known members are Clarias batrachus (walking catfish) and Clarias gariepinus (African sharptooth catfish). Members are typically medium to large, elongated, scaleless or partly scaly fishes with barbels around the mouth and a long dorsal fin.

They possess an airway system that allows breathing atmospheric air, enabling survival in waters with low oxygen and, in some cases, short excursions onto land. This adaptation, along with tolerance for warm, stagnant habitats, helps Clarias species colonize diverse freshwater environments such as rivers, swamps, ponds, and floodplains.

Clarias species are omnivorous and opportunistic feeders, consuming invertebrates, small fish, detritus and plant matter. Reproduction patterns differ among species, but many spawn during warm seasons with some form of parental care by males guarding eggs or fry.

Economic and ecological notes: Several Clarias species are important for food fish in tropical regions and are widely farmed or fished. Their hardiness and air-breathing ability have led to introductions outside native ranges, where they can become invasive and affect native aquatic communities.

Taxonomy: The genus includes many species with ongoing taxonomic study; identification traditionally relies on morphology and is increasingly aided by molecular methods.