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

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