Secrets of the Clownfish – Nemo’s awesome adventure revealed

Clownfish in an anemone in Siquijor Philippines.

Secrets of the Clownfish

Nemo’s awesome adventure revealed

Siquijor diving with clownfish.

Secrets of the Clownfish

Nemo’s awesome adventure revealed


The birth of Nemo

After Pixar released their successful family movie “Finding Nemo”, followed by another big hit in “Finding Dory”, a small character of our reefs became famous. Today we will talk about the clownfish, better known as Nemo.

This beautiful orange, black and white fish that conquered our hearts, lives in the coral reefs of Southeast Asia, Australia and Japan.

It’s such a complex and unique fish and there is so much to discover about it.

Characteristics of the clownfish

The false clownfish, clownfish, or by its scientific name Amphirion ocellaris, belongs to the family Pomacentridae which includes anemonefishes and damselfishes. It presents a vibrant orange colour but this can variate depending on where (or how deep) they live, with three white bars and black endings on bars and fins.

They are small fishes, the females are the biggest on size and can grow up to 11 cm, but aside of their size, clownfishes are highly territorial and will protect their anemone against bigger fish or even against divers if you come too close.

Clownfishes create a long life lasting symbiosis relationship with anemones and they need one for protection and survival.

Diver observes a clownfish in the Philippines.
Nemos live in shallow warm water, from 5 meter to 15 meters deep.
They are commonly found living in Giant carpet anemones or Magnificent anemones.

Social behavior of the clownfish

As mentioned before, this beautiful fish has a complex way of life.

First of all, they are hermaphrodites, meaning that they can change sex. All clownfishes are born male with the ability to become female if one is missing in the anemone. Once the change is completed the fish can not return to male gender anymore.

Once they’ve grown from larvae state to juvenile fish they will descend from surface water to the reef and start a fight against time to find a new home (their anemone).

Not an easy task for a tiny new arrival! Anemonefishes live in complex societies with hierarchies, and they are active protectors of their homes. If the juvenile manages to enter in the anemone, it will be at the bottom of the pyramid.

There is one female per anemone which is the “queen” and highest authority in the hierarchy, followed closely by an alfa male that is the second biggest habitant of the anemone.

 

All the other males are smaller on size and at the bottom.

 

Only the alfa male is allowed to reproduce with the female. Both will create a monogamy relationship that will last all their life span. 

Clownfish hierarchy with dominant female and alpha male.
Baby Nemo-clownfish eggs ready to hatch.
How cute!

Alfa males are in charge of finding a perfect spot where to lay the eggs. After preparing the place, the male will perform an agressive chase of the female to the right spot. It will take around one to two hours to lay all the eggs.

 

When the female is done putting the eggs it will leave the rest of the job to the male. The father is the one in charge of fertilizing, protecting and cleaning the eggs until they hatch. This can take around eight days.

Fun fact about Amphirion ocellaris

It has been proved in captivity that if the female is removed from the anemone the alfa male will be taking its place by changing gender. The second biggest specimen will take the alfa position continuing the cycle.

Size really matters for this little fish!

 

We invite you to check out the CNRS article for more facts about this incredible habitant of the reef.


Clownfishes and anemones live in a symbiotic relationship

Anemones are a group of marine predatory animals attached to the bottom of the sea. The tentacles of this animal are armed with stinging cells for protection. For some reason, the clownfish is immune to the sting and able to live in them.

This tentacles provide perfect protection from predators for the fish, but what does the anemone get in return? Clownfishes will keep the anemone clean from parasites and other organisms that can present a threat to its host.

The clownfish seems to play bait and attract small fishes to the stinging tentacles of the anemone, and just like that: “DINNER IS SERVED”.

Nemo in is anemone.

A word about the “Finding Nemo” effect

Hand throwing fish in a toilet bowl.

A big success brings a lot of good things, but also a lot of bad ones.


Happily, Amphiprion ocellaris is not in danger and the population is abundant. Nevertheless, after the release of the first movie, the demand of this particular fish for the aquarium market increased. In most cases, new owners didn’t have enough information about proper care for this tiny ones in captivity, resulting in a big number of dead fishes in a short period of time.

In other cases, kids decided to put in practice the film idea of “free them back to the ocean” by flushing them down the toilet. Not like this, kids!

We also saw the impact of the fame brought by the film in human actions on the reef. Everyone love to see a Nemo, it is such a beautiful fish living in a strange colourful home.
Bad practices have been spotted around the world where snorkel guides will bring up to the surface an anemone with clownfish so non-swimmers snorkelers can enjoy the view. THIS IS NOT RIGHT!

Anemone and fishes alike suffer from it and get damage that can cause death. Please keep in mind that the only way to see this fish properly is by putting your face in the water and observe them in their natural habitat from a proper distance.

Everyone love this world and all its wonders.
We should all protect it.