“What the hell is that thing?” you may be saying to yourself, rather loudly. Apparently that thing is called a thetys vagina, and it’s gotta be the strangest name for a sea creature ever.
According to Scripps Institute of Oceanography, the Thetys vagina is the largest species of salp that occurs along the West Coast of the United States. Salps are barrel shaped, often clear, jellyfish-like creatures that feed on phytoplankton. But unlike jellyfish, they have a defined body form.
Thetys vaginas live in temperate and tropical waters of the Pacific, Atlantic, and Indian Oceans, typically around depths of 100m.
The name is said to have come from German naturalist Wilhelm Gottlieb Tilesius von Tilenau who famously accompanied the first Russian circumnavigation of the globe from 1803-1806. Apparently Thetys derives from Tethys, a titan Greek mythology, whose name is often used to refer to the sea in hellenistic poetry. Vagina, at the time of Tilesius’ voyage, also referred to a sheath as opposed to the anatomical sense it’s used in today.