Behavioral interactions between the nonindigenous round goby and young-of-the-year yellow perch.
Behavioral interactions have played an important role in the ecological distribution of a variety of species. These interactions can have profound effects on some species including their elimination from desired habitats, increased predation, reduction in numbers, and reduced recruitment. Consequences of these behavioral interactions will vary depending on the amount of niche overlap between competing species. As nonindigenous species are introduced and become established, it becomes imperative that we understand how they interact with native species to develop a better understanding of how they may impact native biota. Introduction of the round goby Neogobius melanostomus into North America and elsewhere has been implicated in the reduction and extirpation of native species. Round gobies negatively influenced yellow perch Perca flavescens in previous studies. In our study, we documented that round gobies influenced yellow perch behavior in the laboratory. We found round gobies displaced young-of-the-year (YOY) yellow perch from rock shelters when introduced into the tank. We also found reduced rock shelter use by YOY yellow perch intruders when round gobies were present. Round gobies were dominant over YOY yellow perch in every case where interactions were observed to occur between these two species. The most aggressive encounters involved round gobies chasing YOY yellow perch and either attempting to bite or actually biting them. These behaviors could have detrimental consequences wherever YOY yellow perch and round gobies overlap in distribution.