The Comparative Morphology of Conus Radulae: Observation with Scanning Electron Microscopy

Abstract

SEM observations of radulae from twenty-two species of the venomous marine neogastropod Conus reveal structures which reflect feeding in one of three modes. Piscivorous , vermivorous and molluscivorous species each possess radular teeth with structures characteristic of their feeding mode. Information gained from the study of radula morphology supports correlations with feeding in one of the three modes in nature. The teeth can be grouped according to the type of prey consumed. The radular teeth of piscivors are of two general types. In the first, two barbs and a posteriorly directed process with a recurved tip are found at the anterior end. In the second, two barbs are found at the anterior end and the shaft is serrated for most of its length. Molluscivors generally possess radular teeth with two anterior barbs and a shaft which in some species is serrated. The radular teeth of vermivors are charac­ terized by one or two anterior barbs and in most cases a serrated region near the apex. The radular teeth of Conus show considerable variation interspecifically with respect to the anterior extremities (barbs).