Abstract:We evaluated the effects of feeding, starvation, and re-feeding on the number of mucous cells in the intestinal mucosa in juvenile southern catfish (). The total number of mucous cells tended to decrease throughout all intestinal segments in the S0d-64h group, but the decrease was only significant in the proximal intestinal segment<0.05). The number of type II cells decreased significantly in both the mid intestinal segment and the distal intestinal segment (<0.05), whereas the number of type III cells increased significantly in the mid intestinal segment (<0.05). Feeding induces secretion from the mucous cells, resulting in more mucous in the intestinal lumen and vesicles of the mucous cells. There was no significant change in the total number of mucous cells across all intestinal segments, but there were type-specific changes in the number of mucous cells. There was a significant decrease in the number of type I cells and a significant increase in the number of type III cells in the proximal and mid intestinal segments in both the 16 day starvation group and post-refeeding 64 hour group. Conversely, there was an increase in the number of type II cells and a decrease in type IV cells in the mid intestinal segment in the 32 day starvation group and the postfeeding 64 hour group. There was no change in any of the mucosal cell types in the distal intestinal segment following starvation and refeeding. Our results suggest that feeding has an effect on the number of intestinal mucous cells in southern catfish. The segment specific regulation of mucous cells is likely correlated to the differing functions of each segment. The regulation of different types of mucous cells in both the proximal and mid intestinal segments may be a protective adaptation to low food availability.