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In 2003, Disney and Pixar released Finding Nemo – a ended up with a smash hit on their hands.  It grossed over $800 million at the box office, is the top selling DVD of all time, and grabbed an Oscar for Best Animated Feature.

Geared toward a G-rated audience, the plot line is oddly on the scary side.  A family of clownfish is all-but destroyed in a barracuda attack; the mother and all but one child area killed.  The two survivors are Marlin, the father, and Nemo.  Understandabily, Marlin is protective of Nemo, so when Nemo tries to venture off on his own, Marlin’s anger gets the better of him.  The two argue and Nemo ends up scooped up by a scuba diver, destined to be a pet in a dentist’s fish tank.   Marlin (with help) spends most of the remainder of the movie trying to reunite with his captured son.

Of course, the movie is fiction.  And as expected, many points of the movie are factually impossible.  (Talking fish?  Vegetarian sharks?)  Call it artistic license, if you’d like.  Regardless, it’s expected.  But here is one element which, had the movie been factually accurate, would be surprisingly incorrect:  Nemo’s father’s gender.

Clownfish — real clownfish, that is, not the Finding Nemo animations — live in small communities within, and symbiotically with, sea anemones.   They also have an uncommon reproductive pattern called “sequential hermaphroditism,” which requires further explanation.

All clownfish are born as males and without the ability to reproduce.  Within each community there is one female, who is the largest in the group.  (Where the first ever female came from is a chicken-and-egg problem to which we just don’t know the answer.)   There is also one reproductive male.  He is smaller than the female fish but still larger than the rest.   The others?  They stay as-is, in a state of male pre-pubesence.  When the female leaves the community — regardless of reason — the reproductive male’s gender spontaneously flips; he becomes the female.  Similarly, the largest non-reproductive male then begins to mature, becoming the reproductive male for the community.    Atypical, yes, but it’s sustained a clownfish population for centuries.

As applied to Finding Nemo?  When Marlin and Nemo’s family were destroyed by the barracudas, Marlin should have become the community’s female fish.  And, assuming Nemo was the last remaining surivor, he’d become the patron of a new community.   Together, the two would start a new family.

The world is probably better off that Disney and Pixar leveraged their artistic license in this case.

Bonus fact:  Female seahorses deposit upwards of 1,500 eggs into its mate’s brood pouch, making the seahorse one of the few animals whose male carries the babies to term.    The male carries the eggs for nine to 45 days before giving birth to the literally hundreds of baby seahorses in a matter of seconds, as seen here.

From the Archives: Velociraptors Weren’t Very Scary After All: Another movie-made myth about the animal (or dinosaur) kingdom.

RelatedFinding Nemo. It is the second-highest grossing G-rated movie of all time.  Number one?  Toy Story 3.

Originally published

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