GENETIC DISTINCTNESS OF 3 WIDESPREAD AND MORPHOLOGICALLY VARIABLE SPECIES OF DRUPELLA (GASTROPODA, MURICIDAE)

Corallivorous gastropods of the genus Drupella have caused considerable damage to corals at widely separated reefs in the Indo-Pacific. Morphological variability of Drupella species within and between areas has caused taxonomic confusion. To clarify the relationships, we examined allozyme variation at 16 gene loci in samples from Western Australia, Queensland and Japan. Within sites, the species D. cornus, D. rugosa and D. fragum were distinguishable individually by each of 9 to 11 loci, with average genetic identities of about 0.25. The differences extended across sites, whereas the conspecific genetic identities over distances up to 6000 km were 0.86 to 1.00, supporting the view that there are three widespread species of Drupella. Nevertheless, there is much variation within species for allozymes, size, shape and colour.