Zdzisław Zakęś, Krzysztof Wunderlich, Maciej Rożyński, Mirosław Szczepkowski, Marek Hopko
ABSTRACT. Out-of-season reproduction was performed using pikeperch caught in earthen ponds about two months before the natural spawning period. After the ice-cover had melted on the ponds, the fish were caught and transported to a hatchery equipped with a recirculating aquaculture system (RAS). The fish were subjected to environmental stimulation followed by intraperitoneal injections of human chorionic gonadotropin (hCG). The females were divided into two size groups—smaller with body weights (b.w.) of approximately 1 kg (group M) and larger with b.w. of approximately 3 kg (group D). Eggs were obtained from all females, and the mean latency period was determined by the age of the females and ranged from 67 h (group D) to 74 h (group M). The effective fecundity and the percentage of fertilized spawn was also significantly dependent on fish size (more advantageous values were noted in group D). The environmental-hormonal procedure applied to stimulate maturation and ovulation can considered to be effective. The values of the basic indicators of pikeperch artificial reproduction were similar to those obtained during out-of-season artificial reproduction of domesticated specimens of this same species reared in RAS. The increasing demand for pikeperch stock and restocking material means that this method is an alternative solution for producing these kinds of materials.
Key words: human chorionic gonadotropin (hCG), pond pikeperch, hormonal stimulation, environmental stimulation, out-of-season reproduction
Przyjęto po recenzji 19.05.2016 r.