From the Monterey Bay Aquarium: Live jellyfish cam in HD

(This live video is active only during certain parts of the day. Apparently, jellyfish need to sleep too.) Watch as their long tentacles and lacy mouth-arms move smoothly through the water. But don't let these unassuming invertebrates fool you—their graceful trailing parts are covered in stinging cells used for hunting. When their tentacles touch tiny drifting prey, the stinging cells paralyze it and stick tight. The prey is moved to the mouth-arms and then to the mouth, where it's digested.