Competitive Interactions between Round Gobies and Logperch

We examined territorial defense and behavioural interactions between two species of fish resident in Hamilton Harbour: non-indigenous round gobies (Neogobius melanostomus) and native logperch (Percina caprodes). Trials consisted of placing one fish, “the resident” (either a round goby or a logperch), in a tank with a shelter for 24 hours before adding another fish, “the intruder” (either a round goby or a logperch), and recording aggressive …