Male/Female or what?

Clownfish or anemonefish, Amphiprion sp are fishes from the subfamily Amphiprioninae in the family Pomacentridae.

Many people do not kclownfishnow that clownfish are actually transsexuals! Clownfish are hermaphrodites that have both female and male gonads. Once the clownfish are hatched, the female gonads are suppressed and so all clownfish start life as males, no females.

After the early part of their lifecycle, upon finding a suitable host sea anemone, clownfish will settle down on it. The clownfish will gently touches the anemone’s tentacles over a period of several hours or days, until they form a layer of mucus that is resistant to the stings. Usually, a small group of clownfish live in one large sea anemone. And in each sea anemone, there exists a strict hierarchical system between the clownfishes. The highest rank is the female breeder, following next is the male which mate with the female breeder. Only one male clownfish ( which is ranked number two) mate with the female breeder. And at the bottom of the ranks will be up to four smaller, non breeding clownfishes.

clownfish on flickr

Ocellaris clownfish HD video at Haus des Meeres on Flickr – Photo Sharing!

And when the female clownfish die, her mate changes sex and becomes female! At the same time, the largest of the non-breeding clownfish becomes the functioning male. Other fishes also moved up a rank. Another interesting obervations is that clownfish regulate their size in order to remain in the community. Each clownfish will keep its size smaller than the clownfish directly above its rank. Clownfish that grow bigger than clownfish above its rank could be rejected by the community. This adaptation of clownfish ensure continuous reproduction.


” Social hierarchies: Size and growth modification in clownfish,” by  Peter Buston. Nature 424, 145-146, 10 July 2003 URL:

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“Nemo puts clownfish in spotlight,” by Ann Kellan. CNN, Monday, August 4, 2003 URL:

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“Ocellaris clownfish HD video at Haus des Meeres” by john.nousis. flickr from yahoo URL:

(accessed on 07/04/2010)

“Splash Zone Coral Reef Animals” by montereybayaquarium      URL:

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“Cave under Ras Muhammad” by Leigh Cunningham. X-ray MAG57,58 ,2008   URL:

(accessed on 07/04/2010)

“Clownfish” by beest. flickr from yahoo URL:

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