According to a report on Inquirer.net, the clown knifefish (Notopterus chitala), a large and popular ornamental tropical fish, has invaded Laguna de Bay on the Philippine island of Luzon. The fish, which can grow to 20 inches or more and eat any small fish that it can fit into its mouth, is apparently wreaking havoc on the local fishing industry. Asis Perez, head of the country’s Bureau of Fisheries and Aquatic Resources, said the fish is multiplying in the country’s largest freshwater lake and eating the lake’s native species that local fisherman rely on as food and income sources. “It is carnivorous,” Perez told Inquirer. “It will compete with our existing natural fish. We have yet to get a full appreciation of the damage caused by this fish.”
Ornamental fish breeders are being blamed for the release of the clown knifefish in Laguna de Bay. This isn’t the first time that an invasive species has found its way onto the island chain. The Bureau of Fisheries and Aquatic Resources cites the release of plecos into Philippine waters, which was also attributed to ornamental fish breeders.
The fish, which is shaped like a knife and has black spots on its body as it grows older, is native to the Mekong basin of Southeast Asia. This species can grow very large, and as such, will do well in aquariums with other large fish such as the oscar, Jack Dempsey and other similar large tropical fish species. Smaller fish in the aquarium will be eaten.