The effect of feeding on morphological changes in intestine of pike-perch (Sander lucioperca L.)

The pike-perch (Sander lucioperca L) at the age of 18 days were fed for 21 days with three different diets: Aglo Norse (AN), casein-gelatin (Cas), cod meal with gelatin (Mac) and nauplius Artemia salina (Art—control diet). On the last day of the experiment, fish fed Art and AN diets had the statistically significant highest body mass, length, and survival. On the last day of the experiment, pikes fed Cas diet had the lowest folds of the anterior and posterior intestine. In the anterior intestine of fish fed Cas diet was found a statistically significant increase in the proliferation of the enterocytes as compared with fish from other feeding groups. The fish from Mac-feeding group had the largest statistically significant total area of enterocytes and the absorption area of posterior intestine. This was probably the effect of disorders in the intracellular digestion and the stoppage in transportation of the intracellular digestion products into the circulatory system. Moreover, there was found the intensive processes of apoptosis of enterocytes in the fish fed Mac. On the last day of the experiment, fish fed Art and AN had statistically significantly more cells secreting cholecystokinin and gastrin (Gas) as compared with fish from other feeding groups. Results indicate that juvenile pike-perch can be reared and fed commercial diet AN since its 18th day after hatching. Feeding pike-perch Cas and Mac diets did not satisfy nutritional needs of fish, resulting in low survival, growth rate, and pathological changes in the intestine.