AQUACULTURE OF FRY AND FINGERLING OF PIKE-PERCH (STIZOSTEDION-LUCIOPERCA L) - A SHORT REVIEW

This review presents a short survey of pertinent literature on rearing methods of pike-perch fry and fingerlings in ponds, net cages and tan ks. The traditional pond culture results in variable numbers of finger lings, which are sometimes small and are therefore of limited value fo r stocking. Fingerling production can be increased by manipulating the succession of zooplankton and by stocking adequate quantities of fry in the pond. Culture in illuminated net cages in lakes seems to be a p ossibility to produce advanced fry. The rearing of larvae in tanks fol lowing controlled propagation is initially based on feeding natural pl ankton. The artificial diet can only be used successfully several week s later at fingerling size (4-5 cm). High mortality rates of fry and s ymptoms of food deficiency in liver cells indicate unsatisfactory qual ity of larval diets tested until now. Lack of an adequate artificial f eed considerably hampers further development of intensive rearing of f ry. Growth of fry and fingerlings is strongly temperature dependent. G rowth is rather poor at 16-18 degrees C and best between 26-30 degrees C. Although there is a short stage of positive phototropism in fry, o lder pike-perch generally prefer dim light. There is no food uptake at high light intensity and mortalities will occur under such conditions . More research is needed on adequate diets which consider the ontogen etic development of the digestive organs of young fish.