Feeding and swimming behaviour of Bythotrephes cederstroemi Schoedler

grantor: University of TorontoPredatory zooplankton detect prey with mechanoreception, visual cues or chemoreception. The objectives were to quantify swimming behaviour of ' Bythotrephes cederstroemi' under the influence of prey, prey kairomones, and light and to model 'Bythotrephes'' encounter rate with prey from Harp Lake. I used video capture and motion tracking to measure ' Bythotrephes' swimming behaviour with 'Daphnia, Daphnia' kairomones and 'Polyphemus' as prey. I also measured ' Bythotrephes'' reaction distance to prey under different light levels. ' Bythotrephes' swam fastest and in a more directed fashion in the presence of light and prey than in treatments with light or prey only. Also, ' Bythotrephes'' reaction distance increased in higher light levels and thus is likely to use vision as a detection mechanism. Results from the encounter model show that small, slow-moving prey faced the greatest risk from 'Bythotrephes.'M.Sc