Surreal Sea Slug

There are few tidepool creatures more otherworldly than the alabaster nudibranch, Dirona albolineata.

Today I watched an alabaster turn upside down so it could walk its foot across the surface tension at the top of a pool. I've seen other nudibranch species do this walking-upside-down trick, but with its translucent body and glowing white lines, the alabaster made this strange form of locomotion look particularly surreal.