Population Genetic Structure of Octopus vulgaris

Jassoud, A., Lucas M., Insua, T.L., Miliou, A. and Schizas, N. Population Genetic Structure of Octopus vulgaris. Benthic Ecology Meeting 2012.



Octopus vulgaris is an important species in cephalopod fisheries and also in understanding population regulation in marine invertebrates. Despite its importance, little is known about its distribution and genetic connectivity among populations. The distribution of O. vulgaris is cosmopolitan, but this assumption has been recently challenged. In order to address this issue and learn more about the population structure of this species, the patterns of genetic variation of geographically distant populations were compared: the Caribbean Sea (Puerto Rico, Guadeloupe, Curacao, and Dominica), the European Atlantic Ocean (Spain), the Mediterranean Sea (Spain, France, and Greece), Atlantic Africa (Senegal and South Africa), and Japan. A portion of the Cytochrome Oxidase Subunit I (COI) gene was used to determine the genetic differences among the populations. Bayesian COI genealogies resulted in three monophyletic groups: Caribbean, Eurafrican and Japanese. The Japanese lineage is more closely related to the Eurafrican than the Caribbean lineage. A parsimony network analysis of 17 COI haplotypes showed that the three groups do not share common haplotypes. Within the Caribbean lineage, the most common haplotype is shared by all the populations except for Curaçao. The most common haplotype in the Eurafrican group is shared by all populations. The haplotype parsimony network indicated that the Eurafrican lineage and the Japanese group are relatively close (14 mutations), while the Caribbean lineage is isolated from the two other groups. The Caribbean octopus exhibits an average uncorrected divergence of 11.5% compared to the Eurafrican and Japan octopus, whereas the latter groups are only 3.1% different. The amount of divergence observed between the Caribbean Octopus vulgaris and other geographically distant populations suggests the presence of a Caribbean cryptic species and questions the claim that O. vulgaris is a cosmopolitan species.