When behavioural geographic differentiation matters: inter-populational comparison of aggressiveness and group structure in the European perch

Abstract : Domestication is still a long and difficult process and it is particularly impacted by species behavioural traits. Indeed, tolerance to high densities in intensive cultures and sociability are major features which facilitate domestication and influence the effectiveness of aquaculture production. Moreover, behavioural domestication predispositions could change at the intraspecific level. Here, we investigate three essential behavioural traits: aggressive interactions, group structure and activity between three allopatric populations of Perca fluviatilis, a fish species at its nascent stage of production. We highlight inter-populational differences in group structure and aggressive interactions but not in activity. A more cohesive and homogeneous group structure was demonstrated for Finnish populations compared to Lake Geneva at 45-46 days post-hatching. In addition, Lake Geneva presented a higher aggressiveness. These inter-populational differences could be used in European perch aquaculture in order to improve production as well as welfare of individuals.