ALLOZYME DIVERGENCE SUPPORTING THE TAXONOMIC SEPARATION OF OCTOPUS MIMUS AND OCTOPUS MAYA FROM OCTOPUS VULGARIS (CEPHALOPODA: OCTOPODA)

摘要

Taxonomic status and phylogeny of shallow-water octopuses remain to be resolved. Recently the octopod inhabiting Peru and North Chilean waters has been identified on morphological basis as Octopus mimus instead of O. vulgaris. The former shows faint paired ocelli whereas the latter is a non-ocellated species. Another ocellated octopus is O. maya, which is restricted to the Gulf of Mexico. Thirty allozyme loci were studied in O. mimus collected from Peru, O. vulgaris from Spain and O. maya from the Gulf of Mexico, and in two other Spanish octopods (Eledone cirrhosa and E. moschats) which were used as outgroups. Genetic identity values (Nei, 1972) between O. vulgaris and O. mimm-O. maya (mean I = 0.18) were typical of confamilial genera, whereas genetic identity between the two latter species (I = 0.44) was typical of congeneric species. Moreover, neighbor-joining and parsimony trees showed that O. mimus and O. maya constitute a monophyletic clade. These genetic results suggest that O. mimus and O. maya should be considered as belonging to a different confamilial genus than O. vulgaris, and support the hypothesis of both taxa as Panamanian geminate species resulting from an allopatric speciation event associated with the uplift of Central America.