Dietary Overlap between Native and Exotic Fishes revealed through Gut Content Analysis at Head Baloki, Punjab, Pakistan

Abstract

An imminent threat to indigenous freshwater ichthyofauna is the introduction of alien fishes that can alter the behavior, population dynamics and native community structure. Thus, it is necessary to understand their feeding behaviour to avoid any unwanted incalculable loss. At sampling site, Head Baloki feeding habits both of native (L. calbasu, C. catla, L. rohita and C. mrigala) and alien (H. nobilis, H. molitrix, C. carpio, C. idella, C. auratus, O. aureus, O. niloticus and O. mozambicus) species were analyzed through frequency of occurrence and percentage by number from January 2017-December 2019. Results indicated that L. rohita remained herbivorous while L. calbasu, C. catla, C. idella and both C. carpio and C. mrigala were detritivore, planktivore, phytoplanktivore and generalist feeders, respectively. H. molitrix and C. auratus showed planktivorus and generalist feeding behaviour, respectively. Tilapia species enlisted as detritivores Whereas, H. nobilis was generalist feeder. Complex dietary overlap has been observed between different co-existing species. Current study has uncovered some surprising results where diet of O. niloticus was altered as detritus feeder. Change in feeding habit of alien fishes is the strategy to make them successful that is in line with current findings from freshwater ecosystem of Punjab, Pakistan.