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Larval rearing is a crucial step in fish production. However, issues in larval production, such as low growth/survival rate, impede the aquaculture development of many species including Perca fluviatilis. Since allopatric populations of P. fluviatilis exhibit different growth rates for first-life stages, basing fish stocks on populations displaying optimal features in aquaculture conditions could overcome some of these issues. Here, we (i) compare the growth rate in standardised re-circulating aquaculture system conditions and (ii) assess the genetic differentiation using four mitochondrial markers between seven allopatric populations. Our results confirm that key features for aquaculture can vary at the intraspecific level. However, we do not highlight any clear aquaculture trait differences related to genetic differentiation. Therefore, we cannot assess the genetic basis of growth rate differentiation between populations. This paves the way to future studies on aquaculture performances of genetically distinct populations in P. fluviatilis.

International audience; Domestication of new candidate species remains a long and difficult process often resulting in unfruitful attempts. Early steps in most domestication programs often consider species as a unity, disregarding a part of the biodiversity: the wild intraspecific geographic differentiation. Yet, this differentiation can shape local specificities, which could lead to different domestication predisposition or socioeconomic attractiveness between populations. Therefore, considering this population-specific potential could facilitate domestication and subsequent production of new candidate species. Here, we propose a three-step integrative approach to standardize and facilitate new domestication attempts by taking advantage of wild geographic differentiation. The step 1 consists in classifying the wild biodiversity to identify prospective units (i.e. groups of differentiated allopatric populations). The step 2 allows comparing performances of these units in standardized conditions (i.e. rearing system) through a multi-function and multi-trait assessment. Finally, the step 3 highlights units with higher aquaculture potentials through the calculation of an aquaculture potential score. This approach, here applied to fish culture for human consumption, also aims at being extended to other taxa (e.g. crustaceans, molluscs) and other production goals.

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., SCOPUS: ar.j, info:eu-repo/semantics/published

International audience; 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 het-erogeneity, 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.

International audience

International audience; Potential for aquaculture can differ among allopatric wild populations of a species of interest. This make relevant to seek best candidates for fish farming at the intraspecific level. Here, we compare the aquaculture potential among allopatric population groups of the European perch, a species of interest for fish farming. More specifically, we aim at finding population groups with the best performance in larviculture through an integrative approach that allows considering geographic differentiation in domestication processes. A multi-function/trait assessment was performed on three genetically differentiated groups of European perch populations: (i) Danube, (ii) Eastern Europe, and (iii) European Plain. A geographic differentiation was highlighted for six important traits for perch larviculture: survival rate, swim bladder inflation rate, deformity rate, length at hatching, mean of interindividual distances, and change in activity following a stress event. Along with fish farmer-advice-based weighting of the traits, the calculation of an aquaculture potential score allowed identifying the populations from the Danube region as the most interesting to potentially overcome current bottleneck in European perch larviculture.