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The creepy truth behind ‘Finding Nemo’

By Toby Corren, Divemaster and marine biologist.

Diver or not, the fact is everyone loves clownfish. The famous film ‘Finding Nemo’ painted a rosy picture of family harmony in the clownfish world. But the reality is much much stranger, dark and twisted, even, some may say…Read on to find out the bizarre truth about the most famous fish in cartoons.

Dive Nusa Penida Clownfish anemone
No wonder he's looking a little sheepish

Who are clownfish really?

Commonly referred to as Nemo (thanks Disney), they are a collective community of 30 separate species in the damselfish family (Pomacanthidae’s) across 2 genera (Amphriprion: 29 species, and Premnas: 1 species). They inhabit a range of benthic environments from sand flats to coral reefs and are ubiquitous in tropical coastal ecosystems. Here in Indonesia, 13 out of 30 species have been observed and, subsequently, published about in scientific literature. Many of these are commonly found in Nusa Penida, Bali. The results of these studies have given a fascinating insight into the family dynamics of these small fish, and have highlighted the scientific inaccuracy of Disney’s cartoon.

When I grow up I want to be a female

Clownfish display a biological phenomenon known as protandrous sequential hermaphroditism. This, put more simply, signifies that all clownfish are born males. There is then the circumstantial possibility of a sexual upgrade (as we can all agree) to becoming female. Trust me, if you were a clownfish - a dream I know many of us have had - you wouldn’t want to be a dude.

Lady boss

Male clownfish live a troubled existence. Overruled by a matriarchal boss (the female of the group), the family home (anemone) is inhabited by 1 breeding male and 4 non-breeding (also male) subordinates. The lads’ hierarchy corresponds directly to their size. Not only do the gonads of the non-breeders have no functionality, i.e their junk got no spunk (sorry it but it rhymes), but they also modify their growth rate in relation to their immediate superior. This growth regulation prevents the dominant male from considering them a threat to his hierarchy, which would result in eviction from the anemone's toxic safety and exposure to large reef predators (like problematic barracudas, if you remember the cartoon's plot).

The beauty of symbiosis

Clownfish show a textbook example of a symbiotic relationship with their anemone. The anemone gives protection in the form of toxin-infused tentacles, to which the clownfish have immunity. In return for this valuable protection, the clown fish defecates on the anemone. In a human context, this relationship does sound rather bizarre, but anemones literally love this sh*t; they survive off the nutrients as recent studies have shown. Other benefits to the anemone are the riddance from parasites and protection from certain predators. Clownfish are pretty feisty at protecting their home from known anemone for lunch amateurs, like butterflyfish

Nusa Penida Diving Clownfish Nemo anemone
Not as pink and rosy as Disney would have you believe

What Disney didn’t tell you

But anyway, let’s get back to the topic at hand. There is one saving grace in a male clownfish’s depressing existence, and that is the rule of succession. Suppose an older brother or father clownfish perishes to the reef’s many dangers. In that case, the necessity for replacement means the subordinate clownfish’s growth will be stimulated and he will take the place of the larger deceased family member. Most importantly, this applies to the dominant male in the situation of the Queen mother’s death.

If we put this scientific phenomenon into practice and apply it to the situation of finding Nemo, something quite shocking to our human morality would happen:

In the cartoon this happens:

· Nemo’s mother is eaten during a problematic encounter with a barracuda.

· This death results in widower Marlin (Nemo’s father) developing a psychologically damaging system of overprotection resulting in Nemo’s rebellion and departure from the anemone’s (single dad home)’s safety

· This all then leads to the dad himself going on an adventure outside of the anemone after losing and then (spoiler alert) “Finding Nemo”.

In reality, something much more interesting, yet inappropriate for a children’s cartoon, would occur:

· Nemo’s mother’s death would trigger a hermaphroditic shift in Marlin,

· He would then become Nemo’s new mother.

· As a result, Nemo, being the only remaining subordinate male, would rapidly develop working gonads

· And then, without a hint of sentimentality or grief for the mother’s recent passing, Nemo and Marlin would begin an ‘incestuous’ sexual relationship, eventually birthing a whole new family of little Nemos.

Yep, beats Oedipus. Ah, the sea, so full of wonders!

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