Comparison of Multipiscivore Foraging Success on Native and Invasive Prey Fish under Variable Light Intensities

Piscivorous fishes attack and consume a variety of prey; however, few studies have examined interactions multiple predators with prey species. The situational complexity foraging at different times day was explored by examining the paired native (Burbot Lota lota or Smallmouth Bass Micropterus dolomieu) either (Mottled Sculpin Cottus bairdii) invasive (Round Goby Neogobius melanostomus) benthic prey. study allowed comparison pursuit predator (Smallmouth Bass) an ambush (Burbot). Trials were performed under natural relevant lighting conditions downwelling light intensity emission spectrum matched to irradiance 10-m depth in St. Louis River estuary during summer night, civil twilight, sunrise, midmorning. more active initiated 1,510 reactions that resulted successful capture 61 Round 103 Mottled Sculpin, whereas Burbot 475 resulting 24 retentions, including 9 15 Sculpin. percentage retentions greater for (10.9%) than (5%). Reaction probabilities each differed significantly, which two-fold increase attacks on compared within same time period. distances both did not differ regarding species, but reacted from farther away (maximum reaction 159 98 cm, respectively). Greater success has likely caused higher mortality populations due success, while capturing decreases net energy intake.