“Finding Nemo” would have ended very differently if it reflected the true lives of clownfish.
That’s because Nemo’s dad would have turned into a female before he returned from his journey across the ocean, scientists have revealed.
Research presented by the University of Exeter shows that male clownfish – which are a distinctive orange color with blue-white stripes bordered by black – become female to protect their territory and young.
The female of the species are larger and more aggressive than males and have been known to attack sharks.
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 “Finding Nemo,” the adorable protagonist is eaten by a barracuda but his dad, Marlin survives.
Nemo is the remaining baby, but gets lost and is pursued by sharks and narrowly escapes a dentist’s goldfish bowl before finding his way back home.
But in the real fishy world, Marlin would have already become a female and laid a new batch of eggs after mating with a younger male living in the anemone they called home.
Dr. Suzanne Mills, an evolutionary biologist from École Pratique des Hautes Études at CRIOBE in France and Dr. Ricardo Beldade, a marine biologist with Centre National de la Recherche Scientifique at CRIOBE, researched the behavioral, physiological and hormonal changes in anemonefish, or clownfish, over several years in Moorea, French Polynesia.
They presented their findings at the 50th Anniversary Symposium of the Fisheries Society of the British Isles at the University of Exeter.
Mills told marine biologists at Exeter University: “Anemone fish don’t move from their anemone for the whole of their life.”
“The largest individual is the female, and if that female gets predated upon or dies, the male – Nemo’s dad – then changes sex and becomes a reproductive female.”
“So when Nemo finally gets back to his anemone at the end of the film, he’s actually meeting his mom.”
“The female is aggressive to predators and protects the anemone.”
“If she dies or is eaten then the male changes sex over a few weeks.”
“There needs to be lots of hormonal changes to become fully female.”
“When the male has changed sex, the largest sub-adult male becomes her new mate with whom she lays eggs.”
Mills said they were investigating how hormonal, behavioral and physiological characteristics of anemonefish were affected by climate change and human interactions like boat engine noise.
Beldade who studies the behavior and genetics of clownfish in French Polynesia, said: “Because of the sex change the same individual can have an opportunity to breed as a male and a female. The couple defends the anemone together in their own way and they both need each other to survive and reproduce.”