On a record of two alien fish species (Teleostei: Osphronemidae) from the natural waters of Chennai, Tamil Nadu, India

Aquarium trade has been the source of many alien species being introduced into the natural waters of Chennai. Trichopsis vittata and Macropodus opercularis are being reported for the first from Chennai. However, contrary to the propagule pressure theory both these species are not common in the aquarium trade, raising speculations of inter-basin water transfer playing a role in introducing non-native species into an ecosystem.