I visited laboratory „Domestication in Inland Aquaculture“ of Lorraine University in Nancy (France) in 1 – 3 May 2015. During the mentioned visit, I with my French colleagues collected final samples for monitoring of tissue histology from gonads, brain, blood and liver for an experiment concerning to the reproduction study of domesticated and non-domesticated strains of pikeperch broodstock (Sander lucioperca L.). Instead this activity, we started new experiment during my stay in Nancy concerning to final maturation of oocyte stages in pikeperch females with using of different hormonal treatments under controlled conditions.