These "sea slugs" are members of one suborder of soft-bodied, shell-less marine mollusks, which are noted for their often extraordinary colors and striking forms. Scientists have discovered more than 3000 species of these little moving rainbows.
Their wonderful colors are due to the loss of the shell as a protection. Some of them developed colors to achieve a perfect camouflage with their habitat, others on the contrary developed garish flamboyant colors to warn their predators about their toxicity.
