• cephalopods;
  • mirror;
  • sociality;
  • oval squid;
  • brain


Cephalopod mollusks are found virtually everywhere throughout the world's oceans. They are highly mobile invertebrates that have evolved behavioral and morphological defenses against vertebrate predators. Unlike other mollusks, the coleoid cephalopods (octopus, cuttlefish, and squid) possess highly developed nervous systems with huge brains equivalent in size to some vertebrate brains. Cephalopod intelligence is also exhibited by their impressive memory and learning abilities. Why have cephalopods developed such huge brains and cognitive ability? One of the keys to answering this question lies in understanding the social interactions of cephalopods, which have thus far not been well documented. In this paper, I will outline our recent behavioral experiments using mirrors with some cephalopods and discuss these experiments in light of the diversity of social and cognitive behaviors of cephalopods.