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¹ Szent István University, Department of Aquaculture, 2100, Gödöllő, Páter K. Str. 1., Hungary
² Attalai Hal Ltd., Attala Halászház, H-7252, Hungary
³ Tógazda Kft., 2240 Százhalombatta, Arany János Str. 7., Hungary DOI : 10.4194/1303-2712-v15_2_36 Viewed : 3663 - Downloaded : 3198 In this study data on successful propagation of zander (Sander lucioperca L.) from several spawning seasons are evaluated. Propagation was based on stripping of spawners after hormonal induction and rearing of fry in artificial ponds. Fish were injected with acetone-dried carp pituitary extract at a dose of 4.0 mg/kg homogenized in a fish physiological saline. When ovulation was detected, the eggs were stripped and weighed. Eggs were collected from each ovulated female and fertilized with milt from the male. Stickiness of zander eggs was removed before transferring them into Zuger jars. Data collected from four consecutive spawning seasons were analyzed statistically calculating individual and group-based pseudogonadosomatic index (PGSI) values. Reproduction capacity assays were grouped on the basis of three aspects: (1) examination of differences between years, (2) within a reproductive season, and (3) examination of the effects of females’ size. During the four-year trial period eggs were gained from 121 hormonally treated females, 64.7% of the total 187. Based on the data of the investigated period the mean PGSI was 10.7%. At 95% significance level PGSI data of different years were considered to be similar. There were no significant differences between PGSI data collected from different periods of the reproductive season. Previous findings on the positive correlation between the amount of stripped eggs and body weight of females were confirmed (r²=0.103). Correlation was not justified between PGSI and body weight (r²=0.002). Advanced rearing of zander fry in a 2.0 hectare pond was carried out in six consecutive years. Before stocking the nutrient level of the pond was increased by organic manuring and the Copepods were eliminated by insecticides. To prevent cannibalism, four weeks after stocking the advanced fry of zander were harvested. On the basis of the results from six consecutive years, after rearing of advanced fry in a shallow, 2.0 hectare rearing pond for four weeks, the mean survival rate was 13.4 ± 4.37% (mean±SD). By considering our results, breeders can calculate their hatchery's and pond’s production in advance. These results will also be helpful in calculating the total weight of broodstock which must be held in order to produce a specific number of advanced fry. Keywords : Zander, Sander lucioperca L., induced breeding, fry rearing