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.

Rapid expansion of round goby (Neogobius melanostomus) and western tubenose goby (Proterorhinus semilunaris) beyond their native ranges calls for urgent management action, particularly in localities with high introduction possibility of the species. We used a comparative functional response (FR) approach to forecast invader ecological impact. We compared their foraging efficiency in three habitat structures: sand, coarse gravel, and coarse gravel with an artificial plant. Both Neogobius melanostomus and Proterorhinus semilunaris showed type II FR in all habitats. Interspecific comparison showed similar handling times in both the gravel and gravel with artificial plant habitats, suggesting similar per capita impact. Intraspecific comparison showed significantly lower handling times of both predators on gravel substrates. Therefore, their ecological impact in such an environment could be higher. Neogobius melanostomus showed higher attack rates on sandy substrates compared with Proterorhinus semilunaris, while no significant differences were observed on other substrates. Our results highlight the importance of interacting factors in management of ecosystems with multiple invaders, as the elimination of invasive Neogobius melanostomus may lead to utilization of the empty niche by alien Proterorhinus semilunaris with similar ecological impact.

Present research suggests that phenotypic variations and consequent potential differences in suitability for commercial culture are more likely to occur among genetically diverse populations. We investigated diversity in traits important to aquaculture and assessed genetic differentiation based on four mitochondrial markers in three European populations of Perca fluviatilis. Using a transplant approach to standardize conditions and minimize environmental effects on phenotype expression, we compared survival, cannibalism, growth rate, growth heterogeneity, and specific growth rate of the populations to assess whether difference in aquaculture performance (i.e. expression of phenotypical traits that facilitate the rearing of fish and impact the productivity of the farming) is more likely between genetically differentiated populations than between genetically similar populations. We found key traits of performance to differ among allopatric populations, suggesting value in considering geographic source of broodstock. The largest aquaculture performance disparities were observed among genetically differentiated populations. Some lesser differences were observed between allopatric genetically similar populations, possibly the consequence of pre-collection environment, or transgenerational effects.

Knowledge of spatial genetic variability patterns allows improving conservation actions, translocation regulations, and farming productivity. However, these genetic variability patterns are often considered after issues are observed, long after the beginning of production. By taking into account lessons from other species, we investigate the genetic variability of Perca fluviatilis, a species at a nascent stage of production. The genetic variability has been previously studied but, due to discrepancies between conclusions and methodological limits, the spatial distribution of genetic variability in P. fluviatilis has not been demonstrated conclusively. Here, we characterise the genetic variability across 84 West-Palaearctic sampling sites using mitochondrial and microsatellite markers. We aim to provide (i) a genetically-based population structure that could act as an impetus for further production improvement and (ii) guidelines for translocation regulations. Our analyses show an uneven distribution of genetic variability. Based on inter-populational genetic differentiation, we identify five large geographic scale clusters which are further divided into several subgroups. Local genetic diversity mapping highlights a spatial pattern with several hotspots, which has serious implications in the development of appropriate regulations of translocations. Moreover, we here report an association between genetic differentiations and previously reported zootechnical performances. We ultimately propose guidelines for further investigations of population-specific performances in aquaculture and potentially efficient regulations for policy-makers.