In this photo, the jellyfish Pandea rubra may have been surprised by a camera light or in a defensive state, causing it to contract its red mantle and reveal its complex muscle anatomy. When startled it also retracts and coils its long tentacles, which can be up to 6 times its body length. Like many gelatinous, midwater animals, this jelly is host to other animals that live on its body. The tiny animals feed on the food the jelly catches and possibly the jelly itself. See more images of mid-water creatures in our slideshow.