Two Museum Victoria researchers look to have solved a mystery about the Argonaut octopus that has kept scientists since Aristotle deep in pursuit of working out why it has a shell.
Octopus expert Mark Norman and research biologist Julian Finn have discovered that the female Argonaut uses its shell to collect air from the surface to use as ballast in the waters below. The female octopus creates a shell by secreting calcium carbonate from one of its arms
around herself after mating with the tiny male, whose tentacle penis breaks off and remains in the female. The thin white brittle shell that forms is called the paper nautilus.
Finn and Norman filmed and photographed live animals in the act of trapping their air bubbles into their shell and using it to control very precisely their movement as it weaves its way through the ocean like a tiny submarine. The researchers are continuing to collect data about the Australian species and openly invite your participation with details about how you could help them.
The video we see here was shot by Yasushi Okumura, Japan Underwater Films.
