The University of Western Australia
How ‘Nemo’ got his stripes
Coral reef fishes are renowned for their spectacular colouration, but surprisingly, the function of these patterns is often unknown. The clownfishes (which include the charismatic movie character ‘Nemo’) are particularly intriguing because of their characteristic bold white stripes on an orange background, and their unique symbiotic relationship with toxic sea anemones. Interestingly, not all clownfishes are orange, and not all have white stripes, which raises the question of why this iconic colouration evolved. In this presentation, I will explore whether the clownfishes’ colouration evolved to serve a social function (species recognition) or a defensive function (e.g. camouflage or warning colouration). I present evidence that the evolution of stripes is associated with the defensive properties of the host anemone. This raises the intriguing possibility that the clownfishes’ iconic colouration might serve as a warning signal that advertises the toxicity of the host anemone.