Transmission electron microscopy shows the gastric epithelium ofStyela clavato comprise at least three distinct cell types. Ciliated mucous cells which form the crest of each stomach ridge produce mucus by an unexpected route. Vacuolated cells lining the ridge sides appear to be absorptive in function. Gastric enzymes are produced by typical protein secreting cells scattered amongst the vacuolated cells. Undifferentiated cells are found in the crypts between ridges. The structure and function of the gastric epithelium inStyelais discussed with special reference to the wider concepts of ascidian gut organization.
展开▼
