Liang Yongjun

Effects of starvation and subsequent feeding on morphological and histological structure of digestive system in Platichthys stellatus

We evaluated the effects of starvation and subsequent re-feeding on the structure of digestive system in Platichthys stellatus.We documented changes in morphological and histological structure by observation of paraf-fin-sectioned gut tissue.Groups of fish(mean weight 26.02±0.30 g) were starved for 5(S5),10(S10),or 15(S15) days.A control group was fed as normal.All fish were held at at(19±1)℃ and 32±1 salinity.We observed changes in the morphological structure of individuals in groups S10 and S15.The gastric volume decreased and the gastric wall thinned;the tube wall of the intestine was thinner and transparent while the mesentery was shrunken.The hepatopancreas was atrophied and its color changed from pink to deep yellow.The changes in structure were more evident in groups S10 and S15 than S5.The height of the epithelial cells,gastric gland cells,and the secretory granules in the stomach all decreased and the cell boundary became blurred.There was a de-crease in the height of the epithelial cells and the rugae in the intestine.The striated border also decreased in height,and was even absent in some individuals.We observed an increase in the number of goblet cells,the he-patic tissue was compacted,and there was a decrease in lipid volume and the number of secretory granules in he-patic cells,while the cell boundary become blurred.We observed some degree of recovery following resumption of feeding.Our results suggest that P.stellatus are able to tolerate 5–10 d starvation,beyond which irreparable damage is likely to occur to the histological structures of the digestive system.