GROWTH AND SURVIVAL OF PIKE LARVAE ESOX LUCIUS L. FED ON BRINE SHRIMP (ARTEMIA SALINA L.) NAUPLII

The purpose of this investigation is to establish the effect of using live Artemia nauplii on the survival and growth of juvenile pike (Esox lucius L.). The experiment was carried out at laboratory conditions in 201 tanks in the course of 20 days. The experimental fish were obtained by means of semi artificial reproduction of pike spawners in tank (4 m(3)). On the 12(fth) day after hatching larvae were transferred to the laboratory and stocked in the experimental tanks at three densities - 10, 20 and 30 pike larvae.1(-1). The larvae from the different variants have been fed ad libitum on Artemia nauplii. The results have shown that Artemia nauplii can be used successfully to feed pike larvae obtained from the artificial and semi-artificial reproduction, when because of the low water temperature the zooplankton collection from ponds and lakes has been difficult. The highest growth rate was achieved at stocking density of 30 larvae.1(-1), which has been probably due to the relatively higher density of the Armemia nauplii given in the tanks at that variant. The survival rate of pike larvae in all variants was good and within the limits of 64-68%, in the third variant being little less because of cannibalism, which have occurred more often during the last 3-4 days of rearing.