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Clownfish and Sea Anemone

Debopriya Bose
The relationship between clownfish and sea anemone is beautiful, yet enigmatic. They share a complex bond of interdependence, which is something we can learn from. This story gives you an insight into the symbiotic relationship between the two.
All clownfish are born male, and they have a choice (which is irreversible) to change their gender, to become the dominant female of their group.
The sea anemone gets its name from the beautiful anemone flower. Unlike its namesake, the sea anemone is a carnivorous water dweller, feeding on fish and shrimp. This polyp is a highly dangerous being, as its tentacles are triggered off by the slightest touch. These venom-filled tentacles, when touched, fire off a harpoon-like filament into their prey.

Big things come in small packages. This phrase is apt while describing a clownfish. Albeit small, this temperamental fish has a beauty of its own. Although so varied, the existence of both these creatures are intricately woven into each other.
Symbiosis refers to a living situation between two organisms, from which both the creatures may or may not benefit. In the case of a clownfish and sea anemone, the symbiosis between them is beneficial for each other.


  • Kingdom - Animalia
  • Phylum - Chordata
  • Class - Actinopterygii
  • Order - Perciformes
  • Family - Pomacentridae
  • Subfamily - Amphiprioninae

Sea Anemone

  • Kingdom - Animalia
  • Phylum - Cnidaria
  • Class - Anthozoa
  • Subclass - Hexacorallia
  • Order - Actiniaria
  • Diversity - 46 families


  • Size - 2 - 5 inches
  • Color - Red, orange, yellow, purple, black
  • Lifespan - 6 - 10 (wild), 3 - 5 (captivity)
  • Habitat - Pacific Ocean, Indian Ocean, Red Sea, Great Barrier Reef
  • Traits - Temperamental, aggressive, territorial
  • Food - Omnivorous
  • Diet - Plankton, algae, mollusks, crustacia, zooplankton, isopods

Sea Anemone

  • Size - 0.71 - 1.12 inches
  • Color - Multicolored
  • Lifespan - 50 years or more (wild), several months (captivity)
  • Habitat - Tropical waters, shallow waters mostly attached to rocks
  • Food - Carnivorous
  • Diet - Small fish, shrimp

Their Symbiotic Relationship

The beauty of the relationship between the two is remarkable. A tiny fish making its residence within the venomous tentacles of the sea anemone seems difficult to fathom. But this is no cruel trick of nature - it is reality!
The reason behind their compatibility is that they have a give-and-take relationship between them. The clownfish, because of its bright colors, attracts prey for the sea anemone to hunt and feed on. In turn, the sea anemone feeds the clownfish with scraps or leftovers from its meals.
Also, the clownfish prunes the sea anemone by eating up the dead tentacles of this polyp, and algae that settles on it. Better water circulation is given to the sea anemone when the clownfish fans its fins while swimming. The feces of the clownfish also provides as a fertilizer to the sea anemone.
Being very territorial, the clownfish drives away polyp-eating fish, thus providing protection to the sea anemone. In return, this polyp provides protection to the clownfish, as the predators of the fish prefer to steer clear of the venomous tentacles of the sea anemone.
Clownfish do not get harmed when they touch sea anemones. This is because the clownfish has a coat of mucus on its skin, which is made of protein instead of sugar. This could be a reason as to why the sea anemone does not consider the clownfish as an enemy.

Facts about Clownfish and Sea Anemone

  • Clownfish like shallow waters and sheltered reefs.
  • They are not found in the Atlantic Ocean.
  • The male clownfish courts the female, lures her into his nest where they mate.
  • The tentacles of a sea anemone contains venom, which is a mix of toxins and neurotoxins.
  • Nematocysts are the cnidae that sting.
  • Sea anemones have a soft, cylindrical body, with a broad, circular foot at the bottom.
  • On the top of its body, it has its mouth surrounded by tentacles with poison, that paralyzes its prey.
  • Although they usually lie attached to rocks and shells in the ocean, they may also slowly crawl the ocean floor with the help of the foot or swim using the tentacles.
  • Some species of sea anemones have their sexes defined, while others are termed as hermaphrodites, as they reproduce through budding and binary fission.


Sea Anemone

  • Butterfly fish
  • Humans
  • Rise in sea water temperature
  • Global trade as ornaments


  • Global climate change
  • Octopus and large fish
  • Eels and stingray
  • Sharks and humans
We can see the beautiful relationship between these two marvels of the sea. Their relationship is proof that different species can live in harmony with each other, in order to ensure their own survival.