There is in the nature of a beautiful view of sea inhabitants as nudibranch Glaucus atlanticus.
One of this group - the Blue Angel, he preys on large marine life, including poisonous and (siphonophores Physalia).
Then it uses its venom to protect themselves.
Lifestyle clam place in constant motion, they are drifting upwards abdomen, thus seeking their own food. Stay afloat aided by a bottle of air, which they swallow especially not to descend
Their blue-blue tint allows you to be unnoticed for predatory birds, their belly is colored in silver, which also masks the fish from the bottom.