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 phy...

Repeated cycles of glaciation have had major impacts on the distribution of genetic diversity of the Antarctic marine fauna. During glacial periods, ice cover limited the amount of benthic habitat on the continental shelf. Conversely, more habitat and possibly altered seaways were available during interglacials when the ice receded and the sea level was higher. We used microsatellites and parti...

Incirrate octopods (those without fins) are among the larger megafauna inhabiting the benthic environments of all oceans, commonly in water depths down to about 3,000 m. They are known to protect and brood their eggs until the juveniles hatch, but to date there is little published information on octopod deep-sea life cycles and distribution. For this study, three manganese-crust and nodule-abun...

The entire skin surface of octopus embryos, hatchlings and juveniles bears scattered tufts tiny chitinous setae within small pockets, from which they can be everted retracted. Known as Kölliker’s organs (KO), disappear before the subadult stage. function these structures during early life is unknown, despite having been first described nearly two centuries ago. To investigate further, general t...

In this paper, we studied numerically both kinematic and dynamic models of a biologically inspired mammal-like octopod robot walking with a tetrapod gait. Three different nonlinear oscillators were used to drive the robot’s legs working as central pattern generators. In addition, also a new, relatively simple and efficient model was proposed and investigated. The introduced model of the gait ge...

The resolution of evolutionary relationships among deep-sea incirrate octopuses has been hindered by the paucity of individuals available for morphological studies and by the lack of tissue samples preserved using fixatives compatible with simple DNA extraction techniques. Evolutionary relationships from 11 species of deep-sea incirrate octopuses were investigated using 2392 base pairs (bp) of ...

The southern blue-ringed octopus, Hapalochlaena maculosa (Hoyle, 1883) lacks a planktonic dispersal phase, yet ranges across Australia's southern coastline. This species' brief and holobenthic life history suggests gene flow might be limited, leaving distant populations prone to strong genetic divergence. This study used 17,523 genome-wide SNP loci to investigate genetic structuring and local a...

In the majority of invertebrates the statocyst consists of a single sack; only in the octopod cephalopods is there one sack inside another, so that one can distinguish endolymph and perilymph as in the vertebrate labyrinth. Even in the decapod cephalopods (squids and cuttlefishes) no inner sack is present. The significance of the two sacks has yet to be determined, but it is clearly of interest...

The 'ctenoglossans' are an enigmatic group of transparent, pelagic octopuses that spend their entire life without touching the seafloor. Molecular and morphological evidence shows that the ctenoglossans have arisen via neoteny, the persistence of larval attributes in the adult form. The ctenoglossans have evolved from the planktonic early-dispersal stages of familiar benthic octopuses. Extreme ...