Aquaculture Reports (Nov 2020)
Reproductive performance in virgin pikeperch (Sander lucioperca L.) females fed different dietary levels of arachidonic acid with respect to the duration of spawning induction
Abstract
Pikeperch (Sander lucioperca) is a species of significant importance for the further development of intensive aquaculture, what makes the total control over species’ reproductive cycle a high priority task. The present study aimed to assess the effect of arachidonic acid (AA) dietary enrichment on the reproductive performance in virgin females (two-years-old; individual weight 1.0 ± 0.2 kg) kept in fully controlled conditions with respect to different time of hormonal application. Two groups of breeders, ARA (fed AA enriched diet) and CTRL (fed control feed), were reared in two separated tanks of the recirculation system over the course of seven months. Five, six, and seven months after the start of trial, batches of five pairs of breeders (in total 15 pairs per each feeding group) from each group were hormonally treated. Ovulations occurred after six and seven months (oocyte diameter range 912−1030 μm), and samples of dry eggs were taken for the analysis of fatty acid profiles. Among the parameters of reproductive success, the embryo survival was significantly affected by the diet, while induction duration affected latency time only. The CTRL group females showed overall higher embryo survival across both reproduction occasions (p = 0.028) than group fed AA enriched diet (35.7 ± 17.1 % and 18.6 ± 13.6 % in CTRL and ARA group, respectively). A significant accumulation of AA was found in ARA group eggs in both reproduction batches. Virgin pikeperch breeders appear to keep at least one month plasticity towards the duration of spawning induction in controlled conditions and optimal oocyte diameter range for artificial reproduction is between 900−1000 μm. Levelling dietary AA with eicosapentaenoic acid during the entire photothermal protocol negatively altered the egg quality.
