Octopodoidea phylogeny

The Octopodoidea phylogeny was inferred using three mitochondrial genes – 16S rRNA (16S), Cytochrome Oxidase I (COI) and Cytochrome Oxidase III (COIII) – and one nuclear gene – Rhodopsin (RHO) – for a total of 61 species. The phylogenetic trees based on a Bayesian framework using Mr. Bayes v3.2 (Ronquist et al. 2012) were performed by means of MCMCMC (Metropolis Coupling Monte Carlo Markov Chains), four chains were run using 10,000,000. The trees were rooted using Vampyroteuthis infernalis as an outgroup. The phylogeny from the partitioned data set is consistent with the current octopus taxonomy. The consensus of 9,000 phylogenetic trees from MrBayes showed high posterior probability values (> 0.95) for most of the nodes. The first group (‘clade 1’) includes primarily cold water and deep-sea species from the families Bathypolypodidae, Eledonidae, Enteroctopodidae, Megaleledonidae. The second group (‘clade 2’) encompasses tropical-temperate and shallow water species from the family Octopodidae.