This is the eggcase of Argonauta argo which was washed up to my feet on Brenton Beach one evening. And not only the eggcase but the octopus inhabiting it as well. I was so amazed about it´s sight and not sure what to do…before I could decide, standing in the waves knee deep with my jeans and some black ink dripping off the animal, it slipped back into the ocean with one last glance out of a one very black eye and left me behind puzzled about what I had just witnessed….and sorry about me holding it´s “house” still in my hand.
Argonauts are a rare find on our beaches. They are also called paper nautiluses, referring to the paper-thin eggcase that the females secrete.
They are found in tropical and subtropical waters worldwide; they live in the open ocean, i.e. they are pelagic. Like most octopuses, they have a rounded body, eight arms and no fins. However, unlike most octopuses, argonauts live close to the sea surface rather than on the seabed.