Animals that live underwater as so different they never fail to astound us. Marine invertebrates may flop like jelly when we see them on land, but in their own environment they can be as rigid as they need to be, thanks to the fluid skeletons they formed by compressing water within their organs. Read about how they work and see some gorgeous underwater pictures at Environmental Graffiti. Link -via the Presurfer
(Image credit: Flickr user Neil Barman)