Growing human population and demands for quality protein source resulted in fully- or over-exploitation of 80% of the world’s fish stocks. This has led to continuous growth of global aquaculture production being one of the fastest growing food-producing sectors. The current freshwater aquaculture production relies mainly on several species (e.g. grass carp, silver carp, common carp, Nile tilapia, Atlantic salmon). Hence, in order to increase the sustainable development of aquaculture, the diversification of fish production is of crucial importance while the European perch (Perca fluviatilis L.) is one of promising candidates. Its high market value along with increasing consumer demands make European perch suitable for recirculating aquaculture systems (RAS). However, despite the fact that the species has been introduced in RAS technology more than two decades ago, the volume of European perch production is still not high enough to meet market demands. Poor growth capacity, small size and fragility of the larvae are usually cited as one of limiting factors. Yet, these traits can be enhanced by implementing the biotechnological practices, e.g. domestication, selective breeding etc.

According to several studies the zootechnical traits are variable among geographically different European perch populations implying that genetically divergent populations show different growth characteristics in controlled conditions. Indeed, genetic improvements, together with the selection of suitable strains can considerably improve the development of profitable percid industry in the near future, yet no comprehensive comparison of growth characteristics of European perch influenced by genetic differentiation has been done to date.

Czech research team (University of South Bohemia in České Budějovice, Czech Republic) together with French colleagues (University de Lorraine in Nancy, France) performed an experiment where they investigate the effects of genetic differentiation on zootechnical traits. Three geographically different European perch populations from the Czech Republic, Slovakia and Poland were compared for survival, growth parameters, and cannibalism in standardized conditions in RAS during 115 days post-hatching (dph). These results were coupled with a genetic assessment based on four mitochondrial markers: cytochrome b, D-loop of control region, 16S rRNA, and cytochrome oxidase I.

The differences obtained during the rearing were mainly observed between genetically differentiated Polish population vs. genetically undifferentiated Slovak and Czech populations. At the end of experiment, specific growth rate of Polish population was significantly higher than in the rest populations. Cannibalism and mortality were similar at 115 dph among all populations, excluding influence of genetic basis on these parameters. However, we also observed small variation in aquaculture performance among fish of genetically similar populations. This could be explained by a) an underestimation of the genetic variation based on analysis of only four mitochondrial markers, b) a consequence of different health status, pre-collection environment, or transgenerational effects. Therefore, further studies are needed to assess the importance of these factors in geographic differentiation of aquaculture performance.

Detailed information can be found in the original article: Vanina, T., Gebauer, R., Toomey, L., Stejskal, V., Rutegwa, M., Kouřil, J., Bláha, M., Lecocq, T., 2019. Genetic and aquaculture performance differentiation among wild allopatric populations of European perch (Percidae, Perca fluviatilis). Aquaculture 503: 139–145.

  

Incubation of  European perch eggs in hatching cages

 

RAS system. Surface skimmers are used for trapping of oil film causing problems with swimm bladder inflation in perch larvae

 

Sampling areas and haplotype distribution of European perch populations. Different colours indicate different haplotypes. Number in brackets indicate the number of specimens sharing the haplotype.