Why are fish so brightly coloured?

'Why are fish so brightly coloured?' This is one of the questions most commonly asked by our guests.
Reef fish are able to see colour. Their bright colours are important in species recognition and in the determination of sex. Some species, such as angelfish, have juvenile patterns that are totally different to the adults. The different colour patterns of juveniles may prevent adults from seeing them as a potential threat to territories or as reproductive partners. They also use their colours to blend with the environment is an import way to ambush prey and to hide from predators.