Feeding Efficiency of Larvivorous Fish on Mosquito Larvae: A Comparison between Indigenous and Exotic Species in Assam, India
Abstract
Aims: The study aims to compare the feeding efficiency of three indigenous and two exotic fish species commonly available in the Northeastern region of India, using 4th instar mosquito larvae as prey, under controlled conditions in aquaria. The objective was to identify the most effective species of fish for potential use as biocontrol agents of mosquitoes. Study Design: The design is based on an experimental comparative study. The predatory efficiency of each of the selected fish species was determined using a 5L transparent aquarium. Place and Duration of the Study: The experimental setup for the present experiment was located at Dergaon Chariali, Golaghat, Assam, India, from March to June, 2025 Methodology: Heteropneustes fossilis, Mystus vittatus, and Anabas testudineus were the indigenous fish species and Hyphessobrycon flammeus and Carassius auratus were the exotic ornamental fish species chosen for this study. The indigenous species were collected from natural water bodies with the help of local fishermen, while the exotic species were procured from a neighboring aquarium store. Fourth instar larvae of mosquitoes were collected and used as prey at different densities (20, 50, 100, 200 larvae per aquarium). Each species was subjected to a feeding trial in replicates, and the number of consumed larvae was calculated to assess the feeding efficiency. Results: The indigenous fish species H. fossilis exhibited significantly higher predation efficiency (76.5% at highest density), followed by M. vittatus and A. testudineus. On the other hand, the exotic species showed minimal larval predation with C. auratus and H. flammeus consuming only 4.5% and 1.5% respectively at the highest density. Conclusion: From the present experiment, we concluded that the indigenous species of fish, particularly H. fossilis and M. vittatus, are promising candidates for use as biocontrol agents of mosquitoes in control and natural water bodies. Further study is recommended to determine the ecological viability of these species in an integrated vector management programme.