SEM studies on the radula of the marine shelled gastropods in the potamididae

Abstract

The radular teeth of Telescopium telescopium, Cerithidea obtusa, Cerithidea cingulata and Cerithidea rhizoporarum in Potamididae have been studied by SEM. They are taenioglossate. Each row of radular teeth of Telescopium telescopium and Cerithidea cingulata consists of seven primary teeth, while those of Cerithidea obtusa and Cerithidea rhizoporarum have nine primary teeth. The four species are similar in that the rachidian has a prominent median cusp and the laterals have spatula shaped main cusps which are much larger than the denticles flanked on each side Cerithidea rhizoporarum differs from the other Potamididae studied in the reduction of the central tooth. The difference of cusp arrangement is found in the inner and outer flanking denticles of the lateral teeth among these Potamididae. The marginal teeth of Cerithidea obtusa and Cerithidea rhizoporarum are essentially identical, while those of Telescopium telescopium and Cerithidea cingulata are different. Morphological variation of the radula was not found in this study, but it is too early to conclude that there is no intraspecies variation of the radular element of these species. It is suggested that further investigation in order to compare the radula of the Potamidid snails from different areas is necessary.