The Eurasian perch (Perca fluviatitis) is the most common fish of the Percidae family widely distributed across Eurasia. Perch is a popular target for professional and recreational fisheries and promising freshwater aquaculture species in Europe. However, despite of its high ecological, economical and societal importance, the available genomic resources for P. fluviatilis are lagging behind. Here, we report de novo assembly and annotation of the whole genome sequence of perch which is expected to facilitate exploitation of genomic information for ecological and evolutionary research, selective breeding programs, sustainable fisheries management and conservation.

    Transcriptome analysis of 11 perch tissues

    Perch (Perca fluviatilis) has been used in biological effect monitoring in a programme for integrated coastal fish monitoring at the reference site Kvädöfjärden along the Swedish east coast, which is a site characterized by no or minor local anthropogenic influences. Using a set of physiological and biochemical endpoints (i.e., biomarkers), clear time trends for “early warning” signs of impaired health are noted in the perch from this site, possibly as a result of increased baseline pollution.

    Comparative transcriptome between wild and domesticated Eurasian perch

    Environmental Adaptation of Temperature and Body Shape

    Next generation sequencing (NGS) technologies are extensively used to dissect molecular mechanisms of host-parasite interactions in human pathogens. In contrast, the power of NGS is yet to be fully realizedin ecology as a rich source for formulating and testing new hypotheses. Here, we studied Eurasian perch (Perca fluviatillis) and its eye parasite (Diplostomidae) communities in fourteen lakes that differed in humic contentto test host-parasite-environment interaction. We hypothesised that high humic content would decrease pH and the abundance of the intermediate hosts (gastropods), potentially changing Diplostomidae community structure and potentially affecting perch host immune response. This hypothesis was invoked by RNA-seq data and later cross-validated with PCR-based and extensive metabarcoding approaches. The results demonstrate how humic acid-related changes in the extrinsic environment may shape common parasite communities and host immune response. This study also highlights the utility of integrating RNA-seq and metabarcoding approaches in host-parasite community studies.

    Fish have been highly exposed to radiation in freshwater systems after the Chernobyl Nuclear Power Plant (NPP) accident in 1986, and in freshwater and marine systems after the more recent Fukushima NPP accident in 2011. In the years after the accident the radioactivity levels rapidly declined due to the short half-life of some radionuclides and the decay of long-lived radionuclides. A recent study showed that, after several generations of exposure to environmental radiation at Chernobyl, perch displayed a delay in the maturation of gonads in the most contaminated lakes. Some undeveloped phenotypes were also observed in two of the three contaminated lakes. In order to gain insights into the long term effect of environmental low dose radiation on gonad development, a high throughput transcriptomic approach, including a de novo assembly, was applied to different gonad phenotypes of perch: normal from reference lake, apparently normal from low contaminated lake and apparently normal and undeveloped from more highly contaminated lakes.

    The goal of this study was to investigate the visual system evolution of teleost fishes with a special focus on deep-sea species.