Foraging ecology of Round Goby: impacts on native and non-native prey choices

Session: Finger Lakes Water Quality (2)

Susan Cushman, Hobart & William Smith Colleges, Finger Lakes Institute, [email protected]
Noland Michels, Unversity of Minnesota, Duluth, [email protected]

Abstract

The Round Goby, Neogobius melanostomus, an invasive species now in the Finger Lakes (New York, USA), has been known to forage primarily on dreissenid mussels and Lake Trout eggs, but their impact on other lake invertebrates is not well known. When given choices of benthic and pelagic prey choices, we hypothesized that Round Goby would prefer some invertebrates over others. A series of tank feeding studies were conducted to assess forage preferences using native snails and amphipods, and invasive dreissenids and mysids (Hemimysis anomala). Round Goby did consume Hemimysis when given alone, and amphipods and Hemimysis were both consumed when given together. Gobies preferred some snail families (Physidae) over others, but only snails were consumed when snails and mussels were provided. More Hemimysis were consumed than other prey items when both benthic and pelagic prey options were available. While dreissenid mussels are considered a primary prey item, Round Gobies rarely chose them compared to other prey items. Stomach contents of individuals collectead from an invaded lake and comparison of benthic invertebrate samples from both invaded and uninvaded lakes suggest that Round Goby will forage on available native and invasive prey, and ultimately impact the forage base for native benthics fishes.