Brooding Casper

Remember the little pale octopus nicknamed Casper that wowed the world when it was filmed on the seafloor in the Hawaiian archipelago, 4,000 metres beneath the surface?

A report published in Current Biology reveals that these ghost-like, deep-sea octopods lay their eggs on the dead stalks of sponges attached to seafloor nodules rich in the increasingly valuable metals used in electronics.

The image here shows an octopod brooding its eggs on the stalk of a dead deep-sea sponge. The sponge stalk is attached to a manganese nodule, a naturally forming rock containing commercially interesting metal deposits.