Dispersal of an invasive cyprinid: movement patterns correlated with morphology but not a lab-expressed behavioural syndrome

Dispersal behaviour has important consequences for biological invasions. We assessed morphological and lab-based behavioural traits to test for a behavioural syndrome associated with dispersal in Common Carp, a highly invasive fish. We then correlated these dispersal traits with the opportunistic breaching of a fish barrier and broader movement in the wild. Common Carp were captured attempting to disperse into Cootes Paradise Marsh, a protected wetland in Ontario, Canada. Individual variation was characterized by geometric morphometrics (n = 300) and behavioural trials (n = 44) in a subsample of fish. Video-recorded trials captured measures of boldness, activity, and sociability. A subset of fish (n = 10) were acoustically tagged and released to measure monthly movement patterns. Habitat conditions varied widely in the field, and a rare flooding event allowed fish to bypass a barrier and enter Cootes Paradise Marsh. A multivariate mixed model was used to describe among-individual trait correlations. Common Carp expressed a behavioural syndrome in the lab, where bold individuals were also active and social, but this syndrome was not correlated with morphology or repeatable wild movement. Three telemetry-tracked Common Carp bypassed the fish barrier and entered the protected wetland. Barrier breaching was correlated with monthly distance travelled and negatively correlated with dispersal distance. Other individuals preferred the warm-water canals of the Hamilton Harbour industrial shoreline, where proximity to industry was correlated with a slender body-depth morphology. This study identified a behavioural syndrome, while also identifying traits linked to barrier breaching and potential trade-offs for fish in highly industrialized environments.