Diversity and population genetic structure of Octopus hubbsorum in the Mexican Pacific inferred from mitochondrial DNA sequences

Octopus hubbsorum is the most commonly captured species of octopus on the western coast of Mexico. Despite the commercial importance of this species, management information remains scarce. We determined the genetic diversity and population genetic structure of O. hubbsorum by using mtDNA sequences (COI and ND5). The population structure was not supported by AMOVA or a spatial clustering model. Furthermore, an isolation by distance model did not explain our data. Three haplogroups were detected using a Bayesian assignment; however, the distribution of these haplogroups did not differ among the sampling sites. Our results indicated historical processes of a sudden population expansion, as has been reported for other species in the study region as consequence of climatic changes. However, this expansion did not affect the distribution of the mitochondrial lineages analysed in the study. The weak population genetic structure in O. hubbsorum associated with the life history of the species can explain our results. We suggest that to expand knowledge regarding the genetic structure and population dynamics of O. hubbsorum throughout its range, markers such as microsatellites or single-nucleotide polymorphisms (SNPs) are needed. Thus, on the basis of the information available, the studied population should be assumed to have a weak genetic structure.