This method of protection can keep almost all predators at bay - but not the kaleidoscopically colourful sea slug. Nudibranchs, commonly known as sea slugs, are a group of shell-less marine molluscs.

These are filled with chlorophyll, and the green pigment gives the sea slugs' bodies a leaf-like color. This not only helps them blend in with their surroundings to better hide from predators but ...