Histological studies on the development of the digestive system of the clownfish Amphiprion percula and the time of weaning

This study investigates the histological development of the digestive system of the common clownfish, Amphiprion percula Lacépède 1802, as a means to predict the time when the early juveniles can begin to digest inert feeds. The incubation period is completed within 7 days. At the time of hatching the alimentary canal is advanced and larvae start exogenous feeding immediately. Three days after hatch (DAH) the yolk sac is completely absorbed and at 5 DAH small supranuclear inclusions appear in the hindgut epithelium, suggesting pinocytotic digestion. At 7 DAH gastric glands are established in the epithelium of the stomach and by 9 DAH supranuclear inclusion vacuoles have appeared in the epithelium of the midgut, indicating extracellular digestion and absorption across the lumen. It was concluded that A. percula could only effectively digest artificial feeds from 9 DAH.