When we survey the coral reefs we are lucky to see hundreds of fish with beautiful patterns. The map pufferfish, emperor angelfish and lyretail grouper are some of my favourites. Of course these patterns are there for a reason; to attract a mate, provide camouflage or warn a predator. Equally pretty patterns are found all over the animal kingdom for these very same reasons. Less known however is how these patterns come to be formed. This is the story of how the puffer got his pattern.