Abstract
Simple SummaryThe mechanisms on how alien species naturally affect the native species in the real aquatic environment are infrequently studied. This study explores the potential effects of alien fishes on the native fish community, well-being, and trophic preferences in selected rivers of Klang Valley, Malaysia. We found that alien fishes benefited from the impacts of anthropogenic activities in their surrounding habitats, while their plasticity in feeding habits might help them to invade, survive, and dominate. This study revealed the natural mechanisms on the establishment of alien fish species and their potential ecological impacts on native fishes in the rivers of Klang Valley, Malaysia.This study explores the potential effects of alien fishes on the native fish community, well-being, and tropic preferences in selected rivers of Klang Valley, Malaysia. Following the Aquatic Species Invasiveness Screening Kit assessment, most of the alien fishes (80%) are invasive. The alien species occurrences correlated positively (p < 0.05) with poor water quality, such as rivers with high ammonia-nitrogen and nitrite, but negatively with phosphate and dissolved oxygen. Anthropogenic characteristics, such as rivers with high pollution levels and ease of accessibility to the fish habitat, are mainly associated positively (p < 0.05) with the occurrences of alien fish species. In general, the results of fish stomach contents analyses and their associated indices, together with stable carbon and nitrogen isotopes, revealed domination by alien fishes or diet overlaps between both alien and native fish species. This finding indicates that alien fishes benefited from the impacts of the anthropogenic activities in their surrounding habitats, while their plasticity in feeding habits might help them to invade, survive, and dominate in the rivers of Klang Valley, Malaysia.
Highlights
Alien fishes threaten native biodiversity and health through food and space competition, predation, hybridization, habitat and trophic modifications, and the introduction of diseases [1,2]
Of all the sampled fishes, O. niloticus, Poecilia reticulata, and Mystacoleucus obtusirostris were the most occurring by percentage, occurring at 45.9%, 15.4%, and 12.7%, respectively
The Langat River recorded the highest number of species (10 species), and the lowest numbers were recorded in the Gombak and Tekala Rivers
Summary
Alien fishes threaten native biodiversity and health through food and space competition, predation, hybridization, habitat and trophic modifications, and the introduction of diseases [1,2]. They are usually imported for beneficial purposes, including the need to boost a country’s fish production, the use of these fishes as ornaments, for sports, and biological control of unwanted species [3,4]. Invasive species are regarded as one of the most critical threats to freshwater ecosystems functioning and health [9]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
