Premium
Comparative functional responses of native and high‐impacting invasive fishes: impact predictions for native prey populations
Author(s) -
Guo Zhiqiang,
Sheath Danny,
Amat Trigo Fatima,
Britton J. Robert
Publication year - 2017
Publication title -
ecology of freshwater fish
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.667
H-Index - 55
eISSN - 1600-0633
pISSN - 0906-6691
DOI - 10.1111/eff.12297
Subject(s) - biology , predation , pulex , gammarus pulex , ecology , introduced species , foraging , barbus , trophic level , cyprinidae , invasive species , fishery , zoology , crustacean , fish <actinopterygii> , amphipoda , daphnia
Comparative functional responses ( FR s) can predict impacts of invasive species, including piscivorous fishes, via quantifying their depletion of native food resources as a function of prey density. The utility of FR s for predicting impacts on prey populations by invasive fishes of different trophic guilds was tested here by comparing the FR s of the invaders Cyprinus carpio and Carassius auratus , with three native, trophically analogous fishes, Barbus barbus , Squalius cephalus and Tinca tinca . Chironomid larvae and Gammarus pulex were used as prey items. Predictions, developed from studies on the foraging of C. carpi o and C. auratus in the literature, were that the invaders would have significantly higher consumption rates for chironomids than the native fishes, but not for G. pulex . Mean consumption rates for chironomids were significantly lower for both invaders than B. barbus and S. cephalus , but were similar to T. tinca . Barbus barbus had a significantly lower consumption rate of G. pulex than both invaders, but there were no significant differences between S. cephalus , T. tinca and the invaders. All FR s were type II , with FR curves for the invaders preying upon chironomids never being significantly higher than the native fishes, contrary to predictions. For G. pulex , some significant differences were apparent between the invaders and native fishes, but again were contrary to predictions. These results indicated that when predation impacts of invasive fishes could also be a function of their population density and body sizes, these parameters should be incorporated into FR models to improve impact predictions.