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Clownfish males become fierce females if their ‘wife’ is eaten

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Male clownfish, immortalised in the film Finding Nemo, change sex completely if their female mate is eaten or dies, research by marine biologists shows.

Research presented at the University of Exeter shows that male clownfish – which are a distinctive orange colour with blue-white stripes bordered by black - become female to protect their anemone territory and their anemone fish group.

Female clownfish are larger and more aggressive than males and even attack sharks (see attached video of shark fleeing after being bitten by a female clownfish - copyright Suzanne Mills).

Clownfish, or anemonefish, live in tropical climates on anemones where they stay their entire lives. Male fish tend to look after the eggs and fan them while females act as security guards, scanning the surroundings for predators, issuing warning calls and even launching attacks.

In the film Finding Nemo, a young clownfish’s mother is eaten by a barracuda but his father, Marlin survives. Nemo, the only surviving baby, is then lost and pursued by sharks before eventually finding his way back to his father.

In reality, if a mother clownfish is eaten, its mate changes sex completely and becomes a female, even laying eggs. To ensure the survival of the clownfish group, Marlin would have become Marlene, and mating with a younger male mate from the adolescent population already...

The full text of this article can be purchased from Informit.