Scanning Electron Microscope (SEM) Studies of Radula of Three Gangetic River Mollusca from India

The most important characteristic feature of the buccal cavity in Mollusca (except Bivalves) is the presence of radula, one of the hallmarks of the phylum (Purchon, 1977). It is a chitinous ribbon bearing many transverse rows of firmly fixed teeth. Each row of teeth on the radula normally repeats precisely the number and shape of the teeth in the rows in front of it and behind. The radular teeth are usually in odd numbers because the row consists of a single tooth centrally placed, which is a central or rachidian teeth, with a series of others on either side broadly known as lateral teeth. The shapes of radular teeth are important for determining the effectiveness of the radula as a tool for feeding (Padilla, 1989).