Once I watched a large cuttlefish from above and saw the left side of its body displaying a passing cloud to another cuttlefish under a rock, while the right side was still and camouflaged, pointing out to sea. Cuttlefish’s color changes often occur in combination with changes to the shape of their body and skin. Sometimes they swim around with dozens of “papillae,” or folds of skin, sticking straight out from their back. These look like tiny versions, an inch or so high, of the plates on the back of a stegosaurus. These papillae have nothing hard inside them, and can be produced in a second.
...more
