Introduction of Invasive Peacock Bass (Cichla Spp.), Its Rapid Distribution and Future Impact on Freshwater Ecosystem in Malaysia

Abstract

Malaysia is recognised among the mega-diversity countries with the abundance of various freshwater species. Malaysian freshwater biodiversity is under threat after the introduction of an invasive peacock bass. The presence of this predator could challenge the coexistence of the native species. In the current review, the most important aspects regarding peacock bass threats to the biodiversity future of local species are addressed. Four non-native species of peacock bass are presently recognised in Malaysia. To date, the peacock bass species expand to all parts of Peninsular Malaysia with no records yet found in Kelantan and Borneo. Invasion success is more susceptible in Malaysian lakes (84.38%) compared to the dams, rivers and reservoirs. The mode of rapid expansion of this species is highly connected to the sport fishing and anglers. A propagule pressure, favourable habitat, prey abundance and feeding behaviours are responsible factors for the successful establishment of this species in Malaysia. The species are generalist feeders and piscivorous in nature. It is difficult to eradicate peacock bass since it provides physical jobs (recreation and tourism). However, the damage the species will cause in future is unpredictable. At this point, proper management of this species must be implemented to reduce its population. This could be achieved through updating checklists of freshwater bodies, improving monitoring systems and public awareness.

Genetic Variability of Wild Populations of Invasive Redclaw Crayfish (Cherax quadricarinatus) von Martens 1868 Across Peninsular Malaysia

“…Although only single sampling location represented the river in the current study, however, most previous studies reported the wild populations of redclaws from the streams and lakes (Idrus et al, 2021;Sallehuddin et al, 2021). Turbid nature (low transparency) of most rivers in Malaysia (Khaleel et al, 2021) could be a possible factor unsuitable for the redclaw to establish in the river habitats.…”

Multiple Introduction and High Genetic Diversity: Drivers for Successful Establishment of Invasive Peacock Bass (Cichla spp.) in Peninsular Malaysia

“…that have invaded the entire freshwater bodies examined except for Malacca state where only C. temensis existed. Deliberate introductions by local anglers seem to be the main explanation for the expansion of these species in Malaysia [7].…”

“…Hence, too much angling pressure could be a reason for the number of haplotypes found in Tasik Prima (Selangor), Empangan Timah Tasoh (Perlis) and Tasik Raban (Perak). In Malaysia, Perak and Selangor are hotspot areas for tourist and anglers [7], which may probably increase the chances of Cichla spp. recurrent event of new introduction.…”

“…Although the introduction was well intended by anglers, Cichla spp. are not considered as food fish in Malaysia [7]. Hence, the species are now widely regarded as a threat to the native species in Malaysia's freshwater ecosystems.…”

“…In contrast, anglers are the main agents that promote the introduction and increase releases of Cichla spp. for quenching their catching desire in Malaysia[7]. Therefore, more variations are expected to occur among the species introduced artificially compared to those arrived accidently.Although a single introductory event involving many individuals can lead to the emergence of multiple haplotypes in the population[39].…”