You might think that deep-sea sponges would be about as active as the one sitting in your kitchen sink. But when it comes to motion at the bottom of the ocean, there is more than meets the eye. Time-lapse photography taken over 30 years reveals that certain seafloor animals once thought to be static are actually expanding, contracting, tumbling, and rolling across the seafloor—just very slowly.
Click here for original story, Seafloor images reveal the secret lives of sponges
Source: Phys.org