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.

Although pesticides are typically used to limit pest population, the diversity and nature of their unintentional effects on non-target organisms remain unclear. Better understanding these effects requires to carry out risk assessments on key physiological and behavioural processes specific to beneficial insects. In this study, we addressed this question by exposing mothers of the European earwig (a beneficial insect) to two sublethal doses of deltamethrin (a common pesticide in agriculture) during family life and measured the short-and long-term effects on a series of behavioural, physiological and reproductive traits. Somewhat surprisingly, our results first revealed that high and low doses of deltamethrin enhanced mothers' future reproduction by augmenting their likelihood to produce a second clutch, shortening the number of days until its production, and increasing the resulting number of eggs and their hatching rate.Conversely, the high dose of deltamethrin was detrimental, as it limited maternal brood defence, and reduced food consumption and expression of self-grooming. Finally, other traits were independent of deltamethrin exposure, such as three proxies of family interactions (i.e. distance to the brood, occurrence and duration of mother-offspring contacts), mothers' walking distance, and mother weight gain during family life. Our study overall demonstrates that sublethal exposure to a pesticide such as deltamethrin can have both positive and negative effects on non-target beneficial insects. It thus emphasizes that focusing on narrow parameters can lead to misleading conclusions about the unintended impacts of pesticides in treated agro-ecosystems and call for better considering this parameters diversity in integrated pest management programs.

in agriculture, diversifying production implies picking up, in the wild biodiversity, species or populations that can be domesticated and fruitfully produced. two alternative approaches are available to highlight wild candidate(s) with high suitability for aquaculture: the single-trait (i.e. considering a single phenotypic trait and, thus, a single biological function) and multi-trait (i.e. considering multiple phenotypic traits involved in several biological functions) approaches. Although the former is the traditional and the simplest method, the latter could be theoretically more efficient. However, an explicit comparison of advantages and pitfalls between these approaches is lacking to date in aquaculture. Here, we compared the two approaches to identify best candidate(s) between four wild allopatric populations of Perca fluviatilis in standardised aquaculture conditions. our results showed that the single-trait approach can (1) miss key divergences between populations and (2) highlight different best candidate(s) depending on the trait considered. In contrast, the multi-trait approach allowed identifying the population with the highest domestication potential thanks to several congruent lines of evidence. nevertheless, such an integrative assessment is achieved with a far more time-consuming and expensive study. therefore, improvements and rationalisations will be needed to make the multi-trait approach a promising way in the aquaculture development. The emergence of agriculture is one of the most important evolutions in human history. It was enabled by wild species domestication 1. Domestication is the process in which groups of individuals are bred in a human-controlled environment and modified across succeeding generations from their wild ancestors, in ways these become more useful to humans who increasingly control their food supply and reproduction 2. This process ranges from the first trials of acclimatisation to the setting up of selective breeding programmes 3. The main wave of domestication for fishes only started at the beginning of the twentieth century to develop aquaculture (i.e. the farming of aquatic organisms), notably to mitigate provisioning service disruptions due to fishery collapse 3. Aquaculture is the fastest-growing food production sector in the world and now provides about 50% of the world's aquatic food consumption 3. However, the aquaculture development has been criticised, notably because of its negative consequences on environments and its potential unsustainable development 3,4,6. Despite the numerous attempts to domesticate new fish species, one of the main weaknesses of today's aquaculture is its low species diversity