Close Genetic Relationships between Two American Octopuses:Octopus hubbsorumBerry, 1953, andOctopus mimusGould, 1852

Abstract

The octopuses Octopus hubbsorum and Octopus mimus are two species of octopuses that inhabit shallow waters of the eastern Pacific Ocean. The former species is found in the north, from the Gulf of California to Oaxaca, Mexico, whereas O. mimus lives in the south, from Peru to Chile. To infer the phylogenetic relationships between these species we used the mitochondrial genes cytochrome oxidase subunits I and III, and r16S with the aim of comparing their genetic distances with those of other Octopus sp. The genetic distance values between both species estimated per gene or concatenated were low (0%–1.6%) in comparison with other interspecific distances values (4.6%–18.4%). Application of 10× rule showed there is no overlap between intra- and interspecific octopus distances, whereas the application of the 4× rule confirmed that both octopuses belong to the same lineage. The resolved topologies with maximum parsimony and Bayesian approaches clustered the specimens of O. hubbsorum and O. mimus in a single clade with high bootstrap and posterior probability values (100 and 1.0, respectively). These results allow us to suggest that O. hubbsorum and O. mimus could represent the same species.