Feasibility of controlling the accidentally introduced invasive species Chitala ornata in Sri Lanka

摘要

Clown knife fish, Chitala ornata were accidentally introduced to Sri Lankan water bodies through the ornamental fish industry. The species was well established in one major river basin in Sri Lanka by 2003 and now threatens to spread. Impacts of the introduction of Chitala ornata have not been properly assessed so far; however, fishermen complain that the catches of local species have declined in water bodies inhabited by the knife fish. Due to its carnivorous habits, the knife fish is a potential threat to freshwater fisheries, and action is needed to control the population in Sri Lanka. Fish species endemic to Sri Lanka could also be affected by knife fish due to competition, predation and habitat alteration, resulting in loss of biodiversity. Knowledge of the biology of invasive species is needed to develop a strategy to control them (HOWARD 2000). Studies on the reproductive biology of Chitala ornata in the Bolgoda River system were carried out to determine strategies to control its populations in Sri Lanka.