Nav: Home

Researchers solved mystery of clownfish coloration

August 06, 2018

The anemonefish is more familiarly known as the clownfish, as its bright colouration reminds of the face painting of a clown. The striking and unique colouration consists of white stripes on an orange background, but its biological function has remained a mystery thus far. Now, a study by the researchers of the University of Turku and the University of Western Australia has revealed new information on the colouration of the fish.

The clownfish (Amphiprion ocellaris) belongs to the subfamily of clownfish with the same name consisting of approximately 30 different species. All these species live in a close symbiosis with sea anemones. Sea anemones are sessile animals that have tentacles containing toxic stinging cells that help them to capture their prey and protect them from enemies. However, they do not harm clownfishes, and when danger threatens, the fishes seek shelter among the tentacles.

Every clownfish species has adapted to living in a symbiosis with only one single or a few sea anemone species.

"The intensities of the defence reactions of different sea anemone species are very different from each other, and the venomousness of their stinging cells varies considerably. Correspondingly, there are significant differences between the colouration of different clownfish species," says one of the researchers of the study, Evolution Ecologist Sami Merilaita from the University of Turku.

Dr Merilaita and Dr Jennifer L. Kelley, Adjunct Research Fellow in the University of Western Australia, carried out a comparative analysis which dealt with the evolution of the colouration of the fishes, for example, in relation to the characters of the sea anemone species living in a symbiosis with the fish.

"We found a connection between the colouration and the toxicity of the sea anemone species. The clownfishes that have adapted to living in a symbiosis with the more venomous sea anemones carry less white stripes. This shows that the extraordinary colouration and pattern of the fish has a protective function," Kelley says.

According to the researchers, the white stripes help the clownfish to conceal among the tentacles of the sea anemone.

For the fishes hosted by the more venomous sea anemones, the warning function of the colouration is more important that the camouflaging one: the striking colouration of the fishes can function as a warning signal which chases out natural enemies. In nature, the bright colouration of organisms often indicates a high potency of venom.
Original publication:

Scary clowns: adaptive function of anemonefish coloration.
Sami Merilaita & Jennifer L. Kelley.
Journal of Evolutionary Biology.
First published: 06 July 2018.
DOI: 10.1111/jeb.13350

University of Turku

Related Evolution Articles:

Prebiotic evolution: Hairpins help each other out
The evolution of cells and organisms is thought to have been preceded by a phase in which informational molecules like DNA could be replicated selectively.
How to be a winner in the game of evolution
A new study by University of Arizona biologists helps explain why different groups of animals differ dramatically in their number of species, and how this is related to differences in their body forms and ways of life.
The galloping evolution in seahorses
A genome project, comprising six evolutionary biologists from Professor Axel Meyer's research team from Konstanz and researchers from China and Singapore, sequenced and analyzed the genome of the tiger tail seahorse.
Fast evolution affects everyone, everywhere
Rapid evolution of other species happens all around us all the time -- and many of the most extreme examples are associated with human influences.
Landscape evolution and hazards
Landscapes are formed by a combination of uplift and erosion.
New insight into enzyme evolution
How enzymes -- the biological proteins that act as catalysts and help complex reactions occur -- are 'tuned' to work at a particular temperature is described in new research from groups in New Zealand and the UK, including the University of Bristol.
The evolution of Dark-fly
On Nov. 11, 1954, Syuiti Mori turned out the lights on a small group of fruit flies.
A look into the evolution of the eye
A team of researchers, among them a zoologist from the University of Cologne, has succeeded in reconstructing a 160 million year old compound eye of a fossil crustacean found in southeastern France visible.
Is evolution more intelligent than we thought?
Evolution may be more intelligent than we thought, according to a University of Southampton professor.
The evolution of antievolution policies
Organized opposition to the teaching of evolution in public schoolsin the United States began in the 1920s, leading to the famous Scopes Monkey trial.

Related Evolution Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".