Developmental Changes Of Digestive System Structures In Pike-Perch (Sander lucioperca L.)
Division of Ichthyobiology and
Fisheries, Faculty of Animal Science,
Abstract: The present study was undertaken to observe the morphological and functional development of pike-perch digestive system during larval period. The newly hatched pike-perch larvae were used, and the experiment lasted until the 30th day post hatching. The larvae were fed from the 5 day with Artemia sp. nauplii. The fish were sampled and preserved for histological and histochemical analyses. At hatching, the digestive tract of pike-perch was a straight tube and consisted of undifferentiated cells. The mouth was closed, and esophagus was not connected with the intestine. Undifferentiated liver and pancreas cells were situated over the yolk sac. Between the 5 and 7 day post hatching, the digestive tract developed, and liver and pancreas became active. Digestion and absorption of exogenous food in the intestinal enterocytes was observed before the stomach development. The esophageal goblet cells of the pike-perch larvae developed in 1-2 days after the mouth opening, at the onset of endo-exogenous feeding. Lipids were found in the enterocytes of anterior intestine, while protein absorption – in the epithelium of posterior intestine section. Development of stomach, its glands, and pyloric caeca took place between the 15 and 30 day post hatching.
Key words: development, digestive system, histology, pike-perch, larvae, juvenile