Photo of the Day: An emperor shrimp rests on a Spanish dancer nudibranch—a kind of large sea-slug that dances through the water. The shrimp eats parasites off the nudibranch, and in return has a place to live. . . . #POTD #photooftheday #picoftheday #emperorshrimp #shrimp #nudibranch #seaslug #spanishdancer #marinebiology #aquaticanimals #underwater #underwateranimals #pink #symbiosis #wildlife #nature #naturephotography