Finding Nemo Was Right: Clownfish Dads Are the World’s Greatest Fathers

It turns out “Finding Nemo” got more right, scientifically, than we thought. Just like Nemo’s dad, real-life clownfish dads will do anything to protect their offspring.
 

Their paternal instincts are so strong that if you scoop an unrelated bunch of eggs into a bachelor clownfish’s anemone home, he’ll raise them as his own.


 
Any other fish would eat them!

To care for their young, clownfish dads nip debris away from the eggs and fan them to send oxygen-rich water their way.
 

Water You Waiting For?

Sign up for Azula’s newsletter to bring the latest ocean news and crazy-cute animal videos straight to your inbox.

According to researchers, these fish fathers perform 400 of these paternal motions in the span of just 10 minutes.


 
Researchers wanted to learn what part of the brain made clownfish dads so committed. Oxytocin, known as the “love hormone” in humans, is closely associated with maternal bonding.

The researchers found that a molecule that’s almost identical to oxytocin appears to be the driving force behind clownfish fathering. When they blocked the hormone in male fish, the dads stopped tending to their young.
 

Their rate of 400 fans and nips in 10 minutes went down to only 50 once the hormone was blocked.


 
The researchers’ next discovery was even more surprising. They expected to find the same reduction in nipping and fanning when they blocked another, related hormone.

The second hormone they analyzed, called arginine vasotocin, plays a role in regulating dominance and aggression. Researchers predicted those instincts would be important to fatherhood, too.

But when researchers blocked that hormone, the fish spent even more time with their eggs. It turned out clownfish dads had more love to give.
 

Researchers say cutting off that hormone may have reduced the energy clownfish dads had to defend their other love: the sea anemone.


 
Clownfish rarely venture more than a foot away from the sea anemone where they live — another detail “Finding Nemo” got right.

Their homebody lifestyle could be another reason they’re so fiercely defensive of their families — and one more reason Nemo’s dad is so impressive. He went a lot farther than a foot away, after all.