Salp
A salp (plural salps, also known colloquially as “sea grape”) or salpa (plural salpae or salpas[2]) is a barrel-shaped, planktic tunicate. It moves by contracting, thereby pumping water through its gelatinous body, one of the most efficient examples of jet propulsion in the animal kingdom.[3] The salp strains the pumped water through its internal feeding filters, feeding on phytoplankton. ...
https://en.wikipedia.org/wiki/Salp
I could go on and on, they're so different, but I'll just give you the link to the pics and more info on salps. Hope you're finding them as fascinating as I do.
https://www.bing.com/images/search?q=sa ... BasicHover