Latin Name: Amphirion ocellaris
Location: Indo-Pacific Ocean, Red Sea, NW Australia. Can also be found as far North as Japan.
Size: Fully grown 7-8cm long.
Fun Fact: The name “Nemo” appears in the word anemone (A-NEMO-NE)
Appearance
Everyone knows what the clownfish looks like thanks to the very fun adventurous Finding Nemo film. They are a small type of damselfish with an orange body and white vertical stripes that have a thin black outline. They have a set of orange pectoral and vertical fins with black edges. The tail is also mainly orange with a black edge as well.
They tend to be quite shy fish, so when you get close to them they will swim back to their anemone and hide amongst the tentacles. However, if you get too close to them whilst they are nesting you can recieve a little bite from them, they’re not known for being aggressive, they are just protecting their eggs. Now everyone loves to go and get a GoPro video of the fish swimming amongst their anemone. But there is so much to their little lives than meets the eye.
Clown fish are also called anemone fish and there are many different types of anemone fish, so when you’re diving not only do you see Nemo, you can also go meet all his cousins. There are two types of anemone fish that look very similar to each other, the clown anemone and false clown anemone and many divers don’t notice the difference. The best way to tell them apart is by the black outline on the white stripes. The false clown anemonefish have the black line, sometimes this line can be very thin, so you need to look closely. Sometimes the line can be very thick, making it easier to tell which species you are looking at.
Symbiotic Relationships
Mutualism: A symbiotic relationship between two different organisms where both parties benefit from the relationship.
In this case, we have the anemone and the anemonefish. The anemone may look like a plant, but it is also an animal. It comes from the Cnidarian family which also contains the jellyfish, members of this phylum* contain the stinging cells called cnidoblasts. Think of an anemone like an upside down jellyfish where their tentacles face upwards and contain a toxin that irritates humans and other fish. However, the anemonefish are immune to this toxin. When anemonefish come across a new anemone they want to live on, they will rub themselves against the tentacles building up a tolerance to their toxins. The fish are covered in a mucus-like substance on their bodies which help protect them against the anemone’s toxins which other fish aren’t able to do.
The relationship works because the anemone provides protection for the fish and the anemonefish look after the anemone. It has been observed that anemones with fish tend to contain more oxygen which means they are able to grow bigger than an anemone without any fish. When the fish rub themselves against the anemone and swim in and out of the tentacles, they are allowing more oxygen to flow through and this is then absorbed by the anemone.
When the anemone eats, the fish will consume any leftovers which will contain many nutrients that they need. The fish will keep the anemone clean and in return the anemone provides protection for the fish by stinging any potential predators that get too close. This is why they work well together, the fish benefit and so does the anemone.
Diet
The clownfish are quite small fish, so they can only consume food that is smaller than them. Their diet mainly consists of zooplankton, small crustaceans, worms and they will also eat any parasites off the anemone. The clownfish will also eat small fish that fall victim to the anemone stinging tentacles.
Hierarchy and Reproduction
The big boss of the family is the female. She is usually the biggest fish that you will see on the anemone. She will only mate with one male (the biggest male on the anemone). When it comes to laying her eggs, she can’t do this on the anemone, she needs a hard surface and sometimes the fish might need to improvise. If they are lucky, they can lay their eggs under the anemone if it already sits on a rock, however if it is on sand, the fish cannot lay their eggs in the sand, so they need to bring in a hard surface to lay their eggs on. In David Attenborough’s Blue Planet II we can see a saddleback anemonefish using a coconut shell. They push the coconut across the sand until they are able to push it under the anemone for protection. Once she has laid her eggs, the male will then fertilise them and look after the eggs for up to 10 days until they hatch.
The rest of the family will consist of non-mating males and females
What they didn’t tell you in Finding Nemo
All anemonefish are hermaphrodites, they are born as males. The anemonefish will change from male to female when the big boss dies or the next-in-line male becomes bigger and can then take over the anemone.
So, if the film had really stuck to real life, Nemo’s dad Marlin, would have then become a female and become the new boss of their anemone
Other Common Types of Anemone Fish
- Skunk Anemone Fish
- Clarke’s Anemone Fish
- Tomato Anemone Fish
- Red Saddleback Anemone Fish
- Clown Anemone Fish
- False Clown Anemone
Click on image below to enlarge
*Phylum – A classification system used by biologists. Phlyum is the rank below Kingdom and above Class.