How the clownfish's stripes turn out the way they do
Thanks to the movie Finding Nemo, kids these days know what a clownfish looks like. Researchers have discovered that the clownfish's coloration depends on the sea anemone it has a symbiotic relationship with.
Clownfish, with their white stripes, are easily identifiable, despite the fact that the pattern and intensity of the coloration differ amongst the different species.
A research team from the University of Turku and University of Western Australia (UWA) have discovered the reason for this difference.
After a study that involved 27 clownfish species and 10 known species of host anemone, the team discovered that the coloration of the clownfish species have evolved depending on the sea anemone it is living in a symbiosis with. Those in a symbiosis with sea anemones that are more venomous possess less white stripes. In contrast, the clownfish species with more white stripes are those that are found with less venomous sea anemones.
Hence, the clownfish's appearance serves as a signal to potential predators of the sea anemone of the latter's level of potency.
"It's well known that bright colours in animals can be used to warn predators about prey toxicity before they attack," said co-author Dr Jennifer Kelley, an Adjunct Research Fellow from UWA's School of Biological Sciences.
"What we found suggests that the clownfish were using their anemone hosts to generate a warning signal to predators that says beware of their bright colours because they're associated with the venomous anemones," she added.
The findings of the study was published in last month's issue of the Journal of Evolutionary Biology.