Fun Clownfish Facts

Did you love Finding Nemo? Would you like to know more about clownfish? Read on for some fun facts about clownfish including their dirtiest secret, mating habits and a behaviour that will have you rethinking this cute little fish.

Clownfish, sometimes called anemone fish are brightly coloured fish with three white stripes. They can be orange like Nemo, but some species can be yellow and white or even blue and white. There are approximately 28 species of clownfish. They live at the bottom of the Indian and Pacific oceans as well as the Great Barrier Reef and the Red Sea.

Clownfish live in sea anemones and have a symbiotic relationship with them, meaning that they both benefit from each other. The sea anemone has tentacles that sting other fish (and humans) if you touch them, so it is a safe place for the clownfish who are immune to the stinging tentacles. How? The cute little clown fish’s bodies are covered in slimy mucus, yep mucus. Still think Nemo is cute? If you wash the mucous off, the clownfish will get stung by the sea anemone.

The sea anemone paralyzes prey; usually copepods and zoo plankton with their stinging tentacles and clownfish get the leftovers and serve as a house keeper of sort cleaning away the scraps, keeping the anemone clean. Clownfish reciprocate by providing better circulation to the anemone by swimming and by providing the sea anemones with a tasty treat - their poop. This helps feed the sea anemone and in return the clownfish get a built in house keeper. It’s quite the arrangement and both the clownfish and the sea anemone seem to do their part of the “house work.”

Clownfish are far from being world travellers as seen in Finding Nemo for in reality, most clownfish are homebodies rarely venturing more than 2-4 inches from their sea anemone, since if they go further, they risk losing it to another clownfish. You can imagine that this might make it difficult to find a mate to produce baby clownfish. Clownfish live in small groups that usually consist of a monogamous breeding pair and a few non-reproductive “adolescents” and smaller males. When the female dies the dominant male changes sex and becomes the female. This is called protandrous hermaphroditism. While sex changes are common for many fish species, most species are born females then change sex to become male, called proyogynous hermaphroditism. It comes in pretty handy for the homebody fish – no surgery required and no bad dates looking for the “perfect mate.” At this point I think you can guess Marlin’s future in Finding Nemo for real life, but can you really blame Disney for leaving this part out?

Another surprising fact about clownfish is that they are poor swimmers; imagine that, a fish who is a poor swimmer! Who knew! This is another reason that clownfish are homebodies since most fish are good swimmers, clownfish would be easy prey away from the protection of the sea anemone.

Clownfish may look cute, but they are one of the more aggressive fish in the sea! Even though they are only 2 to 5 inches long, they will approach scuba divers to “chase” them away from their anemone. If scuba divers are persistent, clownfish have even been known to bite scuba divers! Fortunately their teeth aren’t very sharp. Most small fish stay away from scuba divers so clownfish are brave fish to “chase” away divers, especially since divers are ~ 1000 times the size of a clownfish. Can you imagine chasing and attacking an animal that was over 1000 feet long with only small teeth as your weapon? By the way, the larger clownfish that are the most aggressive are female – talk about girl power! You may never think of those “cute” little clownfish the same again.

Remember in Finding Nemo for when Nemo was caught by a scuba diver? In real life this is partially true. Over 50% of clownfish pets for sale come from the wild. After Finding Nemo came out, wild clownfish populations decreased by over 75% since so many people wanted clownfish pets. While clownfish are caught by commercial divers, they usually use cyanide which temporarily paralyzes the fish making them easier to catch, but in the meantime killing other fish and destroying coral reefs.

Furthermore, once you have a clownfish pet at home, keeping him alive is tricky. Out of more than a 1000 different types of anemones, only 10 can host clownfish. Many people mistakenly use the wrong type of anemone and the clownfish pet dies. If you love Nemo and friends, enjoy the movie, go to an aquarium where professionals are trained to care for fish or go diving, but do not keep clownfish pets in a home aquarium. If you absolutely must keep clownfish ipets n an aquarium do your research and ensure that you are purchasing captive bred clownfish pets which are hardier than wild ones in an aquarium and are not depleting clownfish and clownfish habitat in the wild.