DISCORDANT PATTERNS OF MORPHOLOGICAL AND GENETIC-DIVERGENCE IN THE AUSTROCOCHLEA-CONSTRICTA (GASTROPODA, TROCHIDAE) SPECIES COMPLEX

Patterns of genetic and morphological divergence were examined among W estern Australian (Abrolhos Islands and Albany) and Tasmanian members of the highly variable 'Austrocochlea constricta' species complex. Ana lyses of allele frequencies at 13 enzyme loci confirmed the presence o f three species within this complex in Tasmania, revealing additional diagnostic differences not previously detected. Where combinations of species sympatry were examined in Tasmania, seven diagnostic loci sepa rated A. constricta and A. brevis, four separated A. porcata and A. br evis, and one separated A. porcata and A, constricta. Western Australi an animals were genetically most similar to Tasmanian A. constricta po pulations, separated from them by genetic distances of just 0.018 (Alb any) to 0.107 (Abrolhos), despite spatial isolation over similar to 30 00 km. These genetic distances, in addition to that separating Abrolho s and Albany populations (0.138), are considered within the range poss ible for allopatric conspecifics. In comparison, genetic distances sep arating A. constricta from sympatric A. porcata (0.191) and A. brevis (0.803) in Tasmania were much larger. However, on the basis of a range of morphological traits, which were species-diagnostic in Tasmania, A brolhos animals most closely resembled A. porcata, and Albany animals appeared intermediate to A. porcata and A. constricta. This suggests A ustralia-wide discordance among genetic and morphological characters o f the 'A. constricta' complex.