Dear friends, Radular characters are specially useful in those families in which they have become highly specialised, like toxoglossa: conidae, turridae and terebridae. Conidae are among the most diverse and highly specialised gastropods from the point of view of the radular characters. Of course, radular diversification has to do with the diet, and in the case of conidae a specific diet has a specific radula, namely piscivorous, molluscivorous, vermivorous or "specialised" (like Conus californicus, for instance). DNA studies have shown that species diversification in conidae is closely related with changes in dietary habits as well. In fact, conidae can be grouped depending on radular characters ranging from "primitive" (no barb, no serration, small and numerous teeth, etc) to highly specialised (more than two barbs, few large teeth, etc.). Of course, ontogenic changes do occur, and these have been documented in a few cases (i.e. Conus ermineus, or Conus fergusoni), hence adult specimens radular characters are to be considered in order to avoid misleading results. ALso, statistic analysis must be used, so the study of a representative sample of a given species or population must be performed in order to verify the consistence in radular morphology, something that usually (and fortunately) occurs among conidae. IN any case, radular morphology in conidae is useful for species separation, but it has to be considered together with other traits: shell morphology, ecology, egg capsules, etc. Manuel Jimenez Tenorio ---------------------------------------------------------------------- [log in to unmask] - a forum for informal discussions on molluscs To leave this list, click on the following web link: http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1 Type your email address and name in the appropriate box and click leave the list. ----------------------------------------------------------------------