The effect of hormonal preparation (gonadotropins vs. gonadoliberins) on pre-seasonally obtained eggs and larvae quality in pikeperch (Sander lucioperca L.)

Although several papers were dealing with intensively reared broodstocks, most of the published artificial reproduction protocols were applied in wild pikeperch breeders. Therefore, we aimed to evaluate the effects of ovulation induction agents, namely human chorionic gonadotropin (hCG) and salmon gonadotropin–releasing hormone analogue (sGnRHa) on the reproductive performance in pre-seasonal artificial propagation of cultured pikeperch. Breeders were harvested from an outdoor in-pond circulation system in mid-September and transferred to indoor facility in late January, conditioned and injected with either 50 μg kg−1 of sGnRHa or 500 IU kg−1 of hCG, with six females in each hormonal group. Stripped eggs from each female were sampled for chemical composition analysis, fertilised with the milt of two males, incubated and obtained larvae were further reared. No significant differences were noticed between the treatments in any of the analysed parameters of embryo survival nor larviculture performance. Rather high differences in intragroup variation were seen between the treatments, expressed in several-fold higher coefficients of variation in embryo survival in experimental and commercial conditions in the hCG group. Eggs obtained from females treated with hCG had a significantly higher lipid content (31.1% ± 2.0%) compared to sGnRHa-treated females (27.4% ± 1.8%). Fatty acid profiles of the eggs revealed differences in total n − 6 and linoleic acid 18:2n − 6 content while n − 3/n − 6 was significantly lower in the hCG group. Gonadoliberins reduced the variability in the spawning outcome. It appears that hormones can modify the eggs’ fat content during the pre-season artificial reproduction.