Mysis diluviana is an important prey item to the Lake Superior fish community as found through a recent diet study. We further evaluated this by relating the quantity of prey found in fish diets to the quantity of prey available to fish, providing insight into feeding behavior and prey preferences. We describe the seasonal prey selection of major fish species collected across 18 stations in Lake Superior in spring, summer, and fall of 2005. Of the major nearshore fish species, bloater (. Coregonus hoyi), rainbow smelt (. Osmerus mordax), and lake whitefish (. Coregonus clupeaformis) consumed . Mysis, and strongly selected . Mysis over other prey items each season. However, lake whitefish also selected . Bythotrephes in the fall when . Bythotrephes were numerous. Cisco (. Coregonus artedi), a major nearshore and offshore species, fed largely on calanoid copepods, and selected calanoid copepods (spring) and . Bythotrephes (summer and fall). Cisco also targeted prey similarly across bathymetric depths. Other major offshore fish species such as kiyi (. Coregonus kiyi) and deepwater sculpin (. Myoxocephalus thompsoni) fed largely on . Mysis, with kiyi targeting . Mysis exclusively while deepwater sculpin did not prefer any single prey organism. The major offshore predator siscowet lake trout (. Salvelinus namaycush siscowet) consumed deepwater sculpin and coregonines, but selected deepwater sculpin and . Mysis each season, with juveniles having a higher selection for . Mysis than adults. Our results suggest that . Mysis is not only a commonly consumed prey item, but a highly preferred prey item for pelagic, benthic, and piscivorous fishes in nearshore and offshore waters of Lake Superior.
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We would like to thank the captains and crews of the R/V Kiyi, R/V Limnos, and R/V Lake Guardian for their hard work in the field with sample collections, Dan Yule and Matt Balge for processing acoustic data, Jack Kelly and the EPA-Mid Continent Ecology Division for providing benthos data. We are grateful to Mary Balcer and Steve Hagedorn of the Lake Superior Research Institute for tailoring an interactive zooplankton database for our use. Comments from Dan Yule, Lars Rudstam, and several anonymous reviewers greatly improved this manuscript. This work was sponsored by the Great Lakes Fisheries Commission with additional support from the EPA Great Lakes National Program Office (IAG: DW14-948-10801 ). This article is contribution 1685 of the USGS Great Lakes Science Center.
- Fish community
- Food web
- Lake Superior
- Prey selection