Redescription of the Flapjack Octopod, Opisthoteuthis bruuni (Cephalopoda: Opisthoteuthidae), from the Southeastern Pacific Ocean and Evolutionary Relationships of Cirrate Octopods

Cirrate octopods are considered to resemble the ancestor of all octopuses. Cirrates inhabit deep ocean and characterized by presence fins, a cartilaginous inner shell single row suckers alternating with pairs cirri thus comprising uniserial biserial cirri. The objective this contribution is improve taxonomy Opisthoteuthis bruuni from southeastern Pacific Ocean suggest new hypothesis cirrate phylogeny. Given that most complete molecular data set for cirrates available in public databases comprised almost exclusively 16S rRNA gene sequences, we compared morphological mitochondrial generated study genus Ocean. Additionally, sequenced chathamensis, mero Luteuthis dentatus southwestern Pacific, as along Cirroctopus mawsoni Antarctic waters. phylogenetic analysis confirm status member family Opisthoteuthidae. This re-description includes first characterization male female adult stage O. bruuni, addition reporting geographic bathymetric range extensions. presents conspicuous features (small terminal short U-shaped shell). Our tree supports three families: Cirroctopodidae, Cirroteuthidae Opisthoteuthidae, which different arrangements previously reported.