Comparative taxonomic evaluation of Thais species (Order: Gastropoda; Family: Muricidae) of Mollusca from Maharashtra coast of India

Based on shell morphology alone, it was difficult to differentiate the species belonging to genus Thais because of large amount of plasticity, observed in the shell characters. The colour of the shells was poorly defined as species identifying character in Thais species. The morphometric and meristic characters of the shell along with radular characters can solve the taxonomic ambiguities in Thais species (Thais lacera; T. blanfordi; T. tissoti; T. rudolphi; T. bufo and T. subnodulosa). The radular morphology was found to be different in each species except in T. rudolphi and T. blanfordi and hence these two species were differentiated based on radular morphology where the first denticle on outer base of the lateral cusp was smaller than other five denticles in T. rudolphi but in T. blanfordi, all were same in size. A deep 'V' shaped notch was present between inner denticle base of lateral cusp and central cusp in T blanfordi, which was found to be a species specific character.