Effect of starvation and re-feeding on the digestive system of Penaeus japonicus Spence Bate, 1888

This study investigated the effects of starvation and refeeding on the histological features of stomach and intestine in Penaeus japonicus Spence Bate, 1888. Five treatment groups of P. japonicus were initially starved for 0, 5, 10, 15 and 25 days (designated as S0, S5, S10, S15 and S25, respectively) and subsequently fed for 15 days. The effect on digestive system was evaluated using epithelial cell height in stomach and intestine as the assessment criteria and significant decrease in epithelial cell height was considered as damage due to starvation. With prolonged starvation period, the structure of stomach and intestine were found compromised. In the 5 days starvation group (S5), the damage of the digestive system was not significant, whereas the damages became significant after 25 days starvation (S25). In the damaged digestive system of shrimp, the boundary disappeared and the cells were found disassembled. The lumen of hepatic tubule in midgut gland enlarged, the number of the R cells decreased, and the cells were found disassembled. After refeeding, the structures in the stomach, intestine and midgut gland recovered, almost similar to the control group except in the 25 days starvation group. Results from the present study provide practical guidelines for feeding pattern during culture of P. japonicus.