Mixed school of sweetlips Š Fabrice Dudenhofer/Coral Reef Image Bank
Colours, patterns, and coral reef fishes By Christopher Hemingson James Cook University
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olouration can tell us a lot about how an organism behaves and interacts within its environment. Whether it is used for maintaining species boundaries, aiding mate selection or providing protection from predators; colouration is critically important. Therefore, it is no surprise that it has remained a central focus of biological, ecological, and evolutionary studies since the times of Charles Darwin and Alfred Russel Wallace. New advances in image analysis techniques have opened the door to a plethora of new studies involving organism colouration. We now have powerful new tools that allow us to analyse the visual appearance of an organism; including both colour and pattern. Measurement of colouration on coral reefs. Coral reefs are one of the most visually diverse ecosystems on the planet. This vast diversity of colour patterns, and the subsequent messages they
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REEF IN REVIEW
represent, have intrigued researchers since the dawn of modern sciences. Professor Justin Marshall (University of Queensland) attempted to decode messages found within the colours of reef fishes. Blue and yellow were the most common colours used by reef fishes. These colours simultaneously matched their respective backgrounds (blue water and the yellow average colour of a healthy coral reef) but also highly contrasted - aiding signalling. Spectrophotometers operate by detecting the intensity of electromagnetic radiation (light) at each wavelength, returning a distribution of light at various wavelengths (colours). Many studies in the field of colouration has used this robust technique. However, it isn’t without its limitations. While it provides extremely detailed measurements of colour, it does not incorporate critical information about the organism’s full visual appearance: its pattern.
