with a sail-like fin running diagonally down the length of the body. Those only recently stranded from the sea still have their rich, cobalt-blue color, a pigment that provides both camouflage and ...

Vibrant, venomous sea creatures that resemble jellyfish are washing ... float—which can be blue, violet or pink—that rises out of the water and is used like a sail to move the creature.

Not only is it not a jellyfish ... and somewhat resembles an old warship at full sail. Man-of-wars are also known as bluebottles for the purple-blue color of their pneumatophores.