The Asian stinging catfish or fossil cat, Heteropneustes fossilis, is a species of airsac catfish found in India, Bangladesh, Pakistan, Nepal, Sri Lanka, Thailand, and Myanmar. In India in the state of Kerala it is locally called as kadu (Malayalam:kadu ) or 'karri' (Malayalam:കാരി). It is highly preferred in Assam and locally known as singhi. In Bangladesh this fish is called Singi Mach, In Sri Lanka, this fish is called hunga (හුංඟා) by the Sinhala-speaking community. H. fossilis is found mainly in ponds, ditches, swamps, and marshes, but sometimes occurs in muddy rivers. It can tolerate slightly brackish water. It is omnivorous. This species breeds in confined waters during the monsoon months, but can breed in ponds, derelict ponds, and ditches when sufficient rain water accumulates. It is in great demand due to its medicinal value.