A Southeast Asian species in the Ganges Delta: on spreading extent of non-native croaking gourami Trichopsis vittata (Cuvier, 1831) in Bangladesh

摘要

The croaking gourami Trichopsis vittata (Cuvier, 1831), a small Southeast Asian freshwater fish, has long been a non-native enigma to the ichthyologists and hobbyists of Bangladesh. The species has been seen regularly in the Ganges Delta and exotic fish keepers are well aware of its presence there, although nothing is known about the source of introduction. Its first scientific documentation in Bangladesh only occurred in 2012 and in India in 2015. In this paper, we report observation records of T. vittata in Bangladesh through field work, and photographic and literary evidence. From March 2014 to August 2017, 33 confirmed observations were made pinpointing 25 different distribution localities. Plotting observations and localities against time indicated that T. vittata , already a proven sturdy invader in Florida, USA, is steadily spreading its range across the deltaic floodplains of Bangladesh.