The COI gene for phylogenetic analysis of the coleoid cephalopods exhibited a high degree of nucleotide sequence variability, with one half of the sites varying in at least one taxon; COI amino acid sequences were highly conserved, but were useful in determining basal-level relationships among the Coleoidea (Carlini et al.
Both MP and NJ analyses provided strong bootstrap support values for the monophyly of the Coleoid cephalopods (98% MP and 98% NJ), and the monophyly of the Family Sepiidae (64% MP and 78% NJ) as well as Family Sepiolidae (95% MP and 96% NJ) (Fig.
Previous investigations of coleoid systematics have attempted to determine relationships within the Sepiida, Octopoda, and Teuthida through phylogenetic analysis of morphologic and molecular character data.
Relationship of some coleoid cephalopods established by 3' end of the 16S rDNA and cytochrome oxidase III gene sequence comparison.
Phylogenetic analysis of cytochrome c oxidase I sequences to determine higher-level relationships within the coleoid cephalopods.
Coleoids were divided into 2 main lineages, Octobrachia and Decabrachia (including Sepiida, Sepiolida, and Teuthida).