Clever Camouflage

Many ocean animals use camouflage to stay safe. The octopus is one of the best. It can change its colour in less than one second. If it sits on a brown rock, it turns brown. If it moves to green seaweed, it turns green. It can even change the texture of its skin to look bumpy like coral.

Flatfish like the flounder use a different trick. They lie flat on the ocean floor and change their colour to match the sand. From above, they are almost invisible. Birds and other fish swim right past them without seeing them.

The shark uses something called "counter-shading". Its back is dark blue or grey, which matches the dark water below when seen from above. Its belly is white, which matches the bright surface when seen from below. This helps the shark both hide from enemies AND sneak up on its food.