Multidimensional niche differentiation might buffer invasion impacts: the case of oligohaline corophiids (Crustacea: Amphipoda) in the Baltic Sea

Abstract Multidimensional niche differentiation might increase the stability of coexistence by reducing overall overlap which have implications on dynamics biological invasions. The oligohaline Baltic Seais inhabited three native and one invasive corophiid amphipod species. These filter feeding crustaceans differ in their substrate preferences salinity optima could potentially allow robust coexistence. However, recent theory predicts that competing species must diverge across all non-substitutable resources (e.g., food space). We measured mesh size four (i.e., distance between bristles filtering setae), revealing considerable differences among natives ( Apocorophium lacustre , Corophium multisetosum C. volutator ), whereas Chelicorophium curvispinum showed strong with A. lacustre. Theory suggests cannot coexist robustly due to particle irrespective is accordance observations local extinctions Nevertheless, ensuing from multidimensional delay competitive exclusion; i.e., spatial separation types decrease intensity competition for food. Our data co-occurring populations indicate be able its character displacement broader tolerance also help persist region. shift .