Diet composition and consumption rate in round goby (Neogobius melanostomus) in its expansion phase in the Trent River, Ontario
- 400 Downloads
We assessed density, gut fullness and prey composition of round goby (Neogobius melanostomus) from three areas in the Trent River (Ontario) representing areas of initial introduction and subsequent expansion. Round goby had been present at the area of original introduction since 2003, and by 2007/2008, their range had expanded upstream and downstream into the outermost reaches sampled in the study. Catch per unit angling effort in nearshore sites indicated that round goby density in the area of original introduction was more than double their density in the upstream expansion area and nearly three times the density in the downstream expansion area. Gut fullness index was lower in gobies from the area of original introduction than for those at the upstream and downstream edges of their expanded range. The most dramatic difference in diet composition was with dreissenids, where large gobies (≥70 mm) occupying the area of original introduction had almost no dreissenid biomass in their guts, whereas dreissenids were the predominant prey type in gobies occupying the two expansion areas. Post-hoc zebra mussel density in the area of original introduction was an order of magnitude lower than in the two expansion areas which, combined with the differences in stomach fullness and prey composition, suggest that local, density-related reduction of this prey type was occurring in the river.
KeywordsDreissenid Invasive species Macroinvertebrate Range expansion
T. Whillans, S.J. Cooke and A. McDonald provided helpful comments on an earlier version of this manuscript. This project was supported by a National Science and Engineering Council Discovery Grant to MGF.
- Charlebois PM, Marsden JE, Goettel RG, Wolfe RK, Jude DJ, Rudnika S (1997) The round goby Neogobius melanostomus (Pallas): a review of European and North American literature. The Illinois–Indiana Sea Grant Program and the Illinois Natural History Survey, ChampaignGoogle Scholar
- Krakowiak PJ, Pennuto CM (2008) Fish and macroinvertebrate communities in tributary streams of eastern Lake Erie with and without round gobies (Neogobius melanostomus, Pallas 1814). J Great Lakes Res 34:675–689Google Scholar
- Lederer AM, Janssen J, Reed T, Wolf A (2008) Impacts of the introduced round goby (Apollonia melanostoma) on dreissenids (Dreissena polymorpha and Dreissena burgensis) and on macroinvertebrate community between 2003 and 2006 in the littoral zone of Green Bay, Lake Michigan. J Great Lakes Res 34:690–697Google Scholar
- Simonovic P, Valkovic B, Paunovic M (1998) Round goby Neogobius melanostomus, a new Ponto-Caspian element for Yugoslavia. Folia Zoologica 47:305–312Google Scholar
- Wootton RJ (1998) Ecology of Teleost Fishes (second edition). Kluwer Academic Publishers, DordrechtGoogle Scholar