The phylogenetic position of Neritimorpha based on the mitochondrial genome of Nerita melanotragus (Mollusca: Gastropoda)

► The mitochondrial gene order and almost-complete DNA sequence of a representative of the Neritimorpha is reported. ► The gene order in Nerita melanotragus differs from that in the vetigastropoda Haliotis rubra only by two tRNA transpositions, from that in the caenogastropod Ilyanassa obsoleta by one tRNA transposition and a large inversion and from that in the cephalopod Octpopus vulgaris by only one tRNA transposition. ► Genome arrangement analyses group Neritomorpha and Vetigastropoda as sister taxa, but with a low support. ► The sister-group taxon of Neritimorpha varied in sequence-based analyses. However, all analyses either supported or did not contradict the hypothesis that Neritimorpha is closer than Vetigastropoda are to either Caenogastropoda plus Heterobranchia.