Clown featherback

The clown featherback (Chitala ornata), also known as the clown knifefish and spotted knifefish, is a nocturnal species of tropical fish with a long, knife-like body. This knifefish is native to freshwater habitats in Cambodia, China, Hong Kong, Laos, Macau, Taiwan, Thailand, and Vietnam, but it has also been introduced to regions outside its native range. It is one of the world's most invasive species.

It is often seen in aquaculture and the aquarium trade, where it is frequently confused with Chitala chitala; the latter species is very rare in the aquarium trade. The clown featherback reaches 1 m (3.3 ft) in length, outgrowing all but the largest aquaria, yet it is popular.