The aim of the project is to identify processes underlying the egg quality and egg ageing process in pikeperch, with the use of molecular analysis. Both aspects are very important from the perspective of reproductive success of this valuablecommercial fish species. The low and/or variable egg quality is currently one of the main constraints toward rapid development of aquaculture of this species, whereas the biological processes regulating egg quality and egg ageing are barely recognized. Within the projectmultidisciplinary approachwill be implemented, which will involvesimultaneous investigation of: (1) developmental competence of the eggs with the use of biological indicators of their quality, (2) transcriptomic profiling of the eggs characterized by different quality and undergoing ageing process and (3) proteomic analysis of eggs (and ovarian fluid obtained with these eggs)characterized by different quality and undergoing ageing process.