Abstract:
The aim of this study was to study the structure and histology of the digestive tract of a green mussel (Perna viridis) and a spotted babylon (Babylonia areolata) by means of conventional light microscope. special staining, and enzyme-histochemical methods. Based on histological criteria, cell types within the epithelia of green mussel digestive tract were identified into five types of ciliated columnar cell, five types of mucus cell, and two types of tubule cell. In the spotted babylon. there were four types of ciliated columnar cell and four types of mucus cell. The enzymes were found in the apical portion of the ciliated columnar cells in the green mussel and the spotted babylon. In addition, enzymes were found in the apical portions of the tubule cells. Alkaline phosphatase, acid phosphatase, and esterase were synthesized and stored within the cytoplasm of the mucus cells type two and type three of the green mussel. However, they were not found in the mucus cells of the spotted babylon. The mucus cells type one of the green mussel and the spotted babylon synthesized and stored the lipase. Changing seasons did not affect the distribution of alkaline phosphatase, acid phosphatase,esterase, and lipase in the digestive tract of the green mussel and the spotted babylon.