Transgenerational effects of temperature increasement on Atlantic cod eggs.

Temperature increasement of fish eggs in aquaculture has been studied for several reasons. In addtion to increase in general knowledge a possibility to reduce incubation time and plan your production in an efficient manner is one of the goals. The previous experiments showed that there are possibilities of reducing incubation time for Atlantic cod without compromising hatching rates or deformities later on. In ipositive effects were measured on survival and growth. The effect seemed to be persistent and this kind of manipulation could last until harvest size. Manipulated groups showed bigger size at three and half year after hatching and could be a possible strategy to a more efficient production of farmed cod. To study possible transgeneration effects eggs from parents that were temperature manipulated were exposed to high and low temperatures during spring and summer 2017. To be able to follow the individual fish through full life cycle we apply for PIT -tagging 1200 fish from this experiment. This fish will then be transferred to commercial cage farm and follow natural production regimes for farmed cod. Reduction in this study was done by not using all the temperature manipulated groups (14 groups) from the previous studies. The present study only used 8 groups, based on results from previous experiments. The experiment is not expected to do any harm to the fish which will grow up in a commercial fish farm.