California Researchers Discover Mysterious, Gelatinous New Sea Slug

This undated photograph, provided by Monterey Bay Aquarium and Research Institute, shows a mystery mollusk (Bathydevius caudactylus), observed by MBARI's remotely operated vehicle (ROV) Doc Ricketts offshore of Central California at a depth of approximately 1,660 meters. MBARI via AP

MONTEREY, Calif.—More than two decades after spotting a mysterious, gelatinous, bioluminescent creature swimming in the deep sea, California researchers this week announced that it is a new species of sea slug.

The Monterey Bay Aquarium Research Institute posted video online of the new sea slug floating gently in the depths.