EFFECT OF TEMPERATURE SHOCK ON THE BEHAVIOUR AND SURVIVAL OF PIKEPERCH (SANDER LUCIOPERCA L.) FRY

M. Gevezova-Kazakova, M. Yankova, T. Hubenova, A. Zaikov

Abstract: The object of the present study was to investigate the thermal shock in pikeperch (Sander lucioperca L.) fry in laboratory conditions. The experiment was carried out with 180 individuals (mean body weight 0.430 ± 0.065 g) in 3 variants with the following initial water temperature: variant 1 - 13°C; variant 2 - 28°C and variant 3 - 8°C. In variant 1 fish were placed in aquaria with water temperature of 3, 8, 18, 23 and 28°C. In variant 2 fish were placed in aquaria with 5°C descending temperature interval to 3°C. In variant 3 the initial water temperature was 8°C and the experimental was 3, 13, 18, 23 and 28°C.
In all variants of the experiment mass mortality of 100% was observed in the transfer of fish in aquaria with water temperature of 3°C regardless of the temperature difference which is 5,10 and 25°C. When pikeperch fry were placed from 28°C to 8°C 20% mortality was reported, in shock change of temperature from 8°C to 23°C - 50% and from 8°C to 28°C - 60%.
In the conditions of the experiment pikeperch fry showed great sensitivity to shock change in water temperature. Decrease in temperature to 3°C or increase with difference ranging from 5 to 25°C is lethal for them. At temperature difference of 15-20°C some of the pikeperch fry were able to survive and mortality ranged from 20 to 60%.

Keywords: fry; pikeperch (Sander lucioperca L.); survival; thermal shock

Date published: 2017-03-20