Chitala ornata

The clown featherback, clown knifefish, or spotted knifefish, Chitala ornata, is a nocturnal tropical fish with a long, knife-like body. This knifefish is native to freshwater habitats in Cambodia, Laos, Thailand and Vietnam, but it has also been introduced to regions outside its native range. It is one of world's most invasive species. It is often seen in aquaculture and the aquarium trade where frequently confused with Chitala chitala; the latter species is very rare in the aquarium trade. Despite its popularity, the clown featherback reaches 1 m (3.3 ft) in length, outgrowing all but the largest aquaria. This species is native to Cambodia, Laos, Thailand and Vietnam, where found in the Mekong, Chao Phraya and Meklong river basins. It has also been introduced to regions outside its native range, including the Philippines, Indonesia, Myanmar, Singapore, Sri Lanka, and Palm Beach County, Florida, United States. Breeding populations exist in Sarasota County, Florida. The clown knifefish is very distinct, with normally silvery gray with a long knife-like body (laterally compressed) and a long anal fin that gives these fish their common name. Mature fish normally have five to ten (or even more) black spots ringed with white that usually decrease in size as the fish grows. These ocellated spots and the lack of faint stripes on the back separate it from Chitala chitala; a species it frequently has been confused with. Albinos and leucistic specimens are seen with some frequency in the aquarium trade.