Controlled spawning of pikeperch, Stizostedion lucioperca, in lake cages
2002
Demska-Zakes, K. (University of Varmia and Mazuria, Olsztyn-Kortowo (Poland)) | Zakes, Z.
The aim of the study was to determine the effectiveness of the cage method in pikeperch propagation with and without hormonal stimulation. A total of 276 fishes were studied. The effects of propagation without hormonal stimulation, expressed as the number of ovulating females, were highly significantly dependent (P0.05) on the stage of oocyte maturity; they ranged from 0 % (stage I) to 100 % (maturity stage IV), with an average value of about 29 %. The application of 400 IU of human chorionic gonadotropin per kg of female body weight synchronized the maturation process, facilitated reproduction in less mature fish (especially those in stage I), and resulted in enhanced spawning effectiveness in which the percentage of resting females was 88 %. Hormonal stimulation significantly (P0.05) shortened the length of the time the fish were held in spawning cages which allowed their multiple use during the spawning season. The amount of obtained eggs ranged from 60x10**3 to 682.5x10**3 and it was positively correlated with female body weight (r**2
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