Taxonomic status of the 'Patella miniata' species complex (Mollusca: Gastropoda) in southern Africa

The species boundaries between members of the southern African 'Patella miniata' species complex (Patella miniata miniata, P. miniata sanguinans and P. compressa) are poorly defined on morphological grounds. Doubt also exists whether all populations of P. miniata miniata constitute a single taxon, with 'P. cf. miniata' having uncertain affinities. The status of P. adansonii (known only from shells) is also obscure. Protein gel electrophoresis was employed to resolve these taxonomic uncertainties. In addition, a population of P. safiana from southern Angola was included in the study as a reference population. Electrophoretic analysis of 16 enzyme loci revealed four distinctive groupings. All populations of P. miniata miniata and P. cf. miniata proved closely related and separated from P. compressa populations at I=0.85; the P. miniata sanguinans populations clustered out at I=0.79; and P. safiana separated at I=0.69. Phylogenetic analyses, using P. safiana as an outgroup, indicated that P. miniata miniata, P. miniata sanguinans and P. compressa form a closely related monophyletic group in which P. miniata miniata and P. compressa are more closely related to each other than either one of them is to P. miniata sanguinans. Morphological analyses (shells, radula, sperm microstructure) revealed differences that mirrored the differences detected by the allozymes. Thus, it was concluded that P. miniata sanguinans and P. miniata miniata warrant full specific status and we therefore raise the former to P. sanguinans. Patella miniata miniata and P. cf. miniata are geographic variants of the same species, P. miniata, and P. adansonii is sunk within this species. Furthermore, the suggestion that P. miniata and P. compressa may be ecomorphs of the same species are not supported and both warrant specific status. Thus, the 'Patella miniata' species complex in southern Africa is a closely related monophyletic group of three species, with P. miniata and P. compressa being more closely related to each other than either one is to P. sanguinans.