Monterey Bay Aquarium Research Institute discovers mystery mollusc in Monterey Bay

Undulating deep in Monterey Bay, the translucent mystery mollusc defied characterization. On Tuesday, scientists at the Monterey Bay Aquarium Research Institute (MBARI) announced their discovery of these ghostly creatures as the first member of a brand-new family of nudibranchs (sea slugs) that floats through the water column instead of crawling along the seafloor.

The mystery mollusc, Bathydevius caudactylus, with its large jellyfish-like hood, snail-like body and finger-like appendages...