The impact of feeding on the results of rearing larval pikeperch, Sander lucioperca [L.] with regard to the development of the digestive tract

The aim of this study was to determine the impact of the period mixed feed (formulated feed + Artemia sp.) is applied to the growth, survival, and digestive tract development of larval pikeperch (larva age – 6 days post-hatch (DPH)). The larvae were divided into three experimental groups and fed mixed feed from 6 to 12 DPH (group I), from 6 to 19 DPH (group II), and from 6 to 26 DPH (group III). After feeding with brine shrimp was discontinued (group I and II), the larvae were fed formulated feed exclusively. During rearing, the mean larval body weight increased from 0.7 to 20 mg (group I) and 25 mg (group III; P < 0.05). Larval survival in the tested groups was similar at approximately 60% (P > 0.05). The highest percentages of deformed larvae were noted in groups II and III (16 and 14%, respectively). Feeding was noted to have a significant impact on the development of the pikeperch digestive tract. The folds in the esophagus and posterior intestine of fish fed natural feed for the shortest period were the highest (P < 0.05). They also had the most intestinal pinocytotic vesicles and mucous cells. The smallest esophagus goblet cells and gastric glands were noted in group I (P < 0.05).