Authors: Kathleen Church Josephine C Iacarella Anthony Ricciardi
Publish Date: 2016/10/08
Volume: 19, Issue: 1, Pages: 425-441
Abstract
The invasion success of introduced species may be limited by competitive interactions with phylogenetically unrelated invaders The round goby Neogobius melanostomus and spinycheek crayfish Orconectes limosus are invasive benthic predators that occupy and defend similar cryptic microhabitats and thus may compete for shelter The round goby expanded throughout the North American Great Lakes within 8 years of introduction whereas another 6 years passed before it had spread through the upper St Lawrence River Here we explore the premise that dense established populations of the invasive spinycheek crayfish slowed round goby colonization of the St Lawrence River We performed a series of videotaped laboratory experiments to determine if round gobies suffer from aggressive attacks or alter their behaviour eg use of shelter and movement in the presence of spinycheek crayfish We also assessed the prolonged effects of food and shelter competition by comparing changes in the submerged mass of juvenile round gobies and spinycheek crayfish in conspecific and heterospecific pairs Contrary to our predictions round gobies more frequently initiated aggressive encounters with spinycheek crayfish whereas the crayfish were more likely to flee or be evicted from their shelters Furthermore round gobies gained more body mass than spinycheek crayfish regardless of conspecific or heterospecific pairing Rather than impeding round goby colonization spinycheek crayfish appear more likely to suffer energetic costs and an increased exposure to predation in the presence of round gobiesThe authors are grateful to N Bayani L Jones A Kestrup and R Kipp for assistance in the field to A Hassan and R Marrotte for assistance in the lab to G Larocque for assistance with the statistical methods and to P Chuard and J Grant for helpful comments on an earlier version of the manuscript This research was funded by the Canadian Aquatic Invasive Species Network CAISN
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