Wallago Attu Great White SheatfishWallago attu from the family Siluridae is a freshwater fish found in South-East Asia. It has been described as one of the world's largest predatory catfish, but this may be an exaggeration. The maximum length is claimed to be 1.5 m (4 ft 11 in), and it is reported to weigh 60kg (130 lb), but these are likely to be exaggerations.
The Wallago attu is probably restricted to the Brahmaputra drainage in India. It is largely nocturnal and occurs over sandy or rocky substrates of rivers, rarely in flooded forests or swamps. Here it feeds on fish, crustaceans, insects, and mollusk.
Like other catfish, the Wallago attu is listed as a vulnerable species on the IUCN Red List. It faces many threats including habitat loss due to dam construction and fishing for its meat. Also, these fish are often caught up in the nets of local fishermen who then sell them for food or who discard them back into the water where they die.
The Wallago attu was first described by Francis Buchanan-Hamilton in 1822 as Silurus attu, and has also been referred to as Wallacia attu and Wallagoo attu. The generic name derives from the Latin "wallago" or "wallaca", meaning 'twister'. This name reflects the catfish's ability to swim against the current by twisting and turning its body. The specific name "attu" is a historical Bengali name for this fish.
Wallago attu has been recorded from Nepal, India (Assam), and Bangladesh. It is currently considered to be restricted to the Brahmaputra drainage in India, its type locality.
Wallago attu is an active nocturnal fish that occurs in large rivers and some lakes and reservoirs with sandy or rocky bottom in the lower reaches of these rivers, near their confluence with bigger watercourses., Bangladesh, Burma (Myanmar), and Thailand. It occurs in the Brahmaputra and Meghna River basins and probably also in the drainage of the Ganges, but its presence there has yet to be confirmed.
It is nocturnal and migratory. It lives in large rivers and some lakes and reservoirs with sandy or rocky bottoms. Juveniles move into the flooded forest during the monsoon season. In winter adults occur over sand or gravel, but they may change locations during the day. During the monsoons, it also moves into the flooded forest to feed.
Wallago attu is threatened by overfishing for its meat. Also, these fish are often caught up in the nets of local fishermen who then sell them for food or who discard them back into the water where they die.
Global wallago attu (great white sheatfish) production
The wallago attu (great white sheatfish) is a species of freshwater catfish native to South and Southeast Asia. It is an important food fish and is widely cultured in Bangladesh, India, Indonesia, Malaysia, Myanmar, Nepal, Pakistan, the Philippines, Thailand, and Vietnam.
Wallago attu is a large fish, growing to a maximum length of 2 meters (6.6 ft) and a maximum weight of 100 kilograms (220 lb). It is grey or brown in color, with large scales and long, fleshy barbels. The fish is found in rivers, lakes, and reservoirs, and is an important food fish in its native range.
In aquaculture, W. attu is typically cultured in earthen ponds, with stocking densities of 10-20 fish per square meter. The fish is omnivorous and feeds on a variety of plant and animal matter, including algae, insects, crustaceans, and small fishes.
W. attu is a popular sport fish, and is also used in traditional medicine. The fish is considered to be of high commercial value, and is an important part of the aquaculture industry in South and Southeast Asia. It is native to South and Southeast Asia, where it occurs in rivers, lakes, and wetlands. It is an important food fish in its range and is widely farmed. The global production of wallago attu was estimated to be about 934,000 tonnes in 2013.