Novel Object Recognition in Octopus maya.

Abstract

The Novel Object Recognition task (NOR) is widely used for the study of memory in vertebrates and has been proposed as a solid candidate for evaluating memory in different taxonomic groups, allowing similar and comparable evaluations between them. Although, in cephalopods, several research reports could indicate that they recognize objects in their environment, so far, it has not been evaluated as an experimental paradigm, which allows evaluating different phases of memory. In this study, we show that Octopus maya can differentiate between a new object and a known one, with high accuracy. We observed that to achieve object recognition, octopuses use vision and touch exploration in new objects, while familiar objects only need to be explored in a tactile way. To our knowledge, this is the first time showing an invertebrate performing the NOR task, in a similar way to how it is performed in vertebrates. These results raise the opportunity to use a simple, fast and widely used task in other taxonomic groups, to assess memory in octopuses.

Characterization of the brain of the Red Mayan octopus (Octopus Maya)

“…It is the case that some lobes related to somatosensory memory have low cell density and simpler morphology than that of adult specimens. These observations could be correlated with behavioral observations since at this age the octopuses show a decreased capacity for memory and response inhibition [27]. However, more studies are needed on the development and maturation of the nervous system of O. Maya, as well as the behavioral and cognitive differences that they could present at different stages of their life.…”

“…Since then, some cephalopod brain atlases have been published, e.g., two from the squids Idiosepius paradoxus [23] and Todadores paci cus [24], one from the long-arm octopus, Octopus minor [25], and recently a comparative analysis between the brains of diurnal and nocturnal octopuses and the vampire squid [26]. These previous works provide good foundations to investigate the nervous system of a particularly useful species as a laboratory model, such as O. Maya [27]. That is why in this work we took on the task of extracting and characterizing the various structures of the nervous system of O. Maya, at the level of lobes and connectivity between them.…”