Symbiosis: The Art of Living Together

Symbiosis: The Art of Living Together

Symbiosis is a term describing any relationship or interaction between two dissimilar organisms. The specific kind of symbiosis depends on whether either or both organisms benefit from the relationship.


3 - 12


Biology, Ecology

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Wild animals need one other to survive. Sometimes they help one other. Other times, they fight. All these relationships are known as symbiosis. There are four main types of symbiosis. Here is how they work.


Imagine you are diving deep in the Pacific Ocean. You will probably see clownfish with bright colors swimming near the bottom. You might also find sea anemones. The relationship between clownfish and sea anemones is called mutualism. This is when two animals help each other out.

Sea anemones have tentacles that sting. When a small animal touches an anemone, the tentacle releases poison. This stuns the small animal. It allows the anemone to bring the animal to its mouth and eat it. Clownfish are safe, though. They have a mucus on their bodies. It stops the tentacles from stinging. So, the clownfish swim comfortably between the anemones.

Other fish want to eat the clownfish. When they see food, the bigger fish come down for a quick meal. These fish are not safe from the anemones, though. They get caught and eaten instead! This way, the anemones get their food. It works out for the clownfish too. The anemones keep them safe.


In commensalism, one animal lives with or inside another animal. The other animal is called the host. In commensalism, animals do not help their host. They do not hurt it either.

One example is barnacles and whales. Barnacles are sea animals with shells. They attach themselves to the skin of whales. This does not seem to bother the whales. The huge whales take the tiny barnacles to areas where there is food. There, they both get to eat tiny animals called plankton.


Parasitism is a harmful relationship. This happens when one animal lives with or inside a host animal. This time, the host does get hurt. The animal hurting it is called a parasite.

Barnacles do not hurt whales. They can be parasites for other animals, though. They can go inside swimming crabs. The crabs don't die, but they get hurt.


Competition is when animals fight over food or space. It can happen between animals of the same type, or species. This is called intraspecific competition. It also happens between different species. This is called interspecific competition.

Coral and sponges are an example of competition. Coral are sea creatures with tentacles. They use calcium to make hard coral reefs. Many animals live on coral reefs.

Sponges are sea creatures that live on coral reefs. If sponges eat too much, the coral will not have enough food. If too many coral die, the reef ends up disappearing. This is also bad for the sponges. They cannot live without a reef.

Humans can hurt the environment too. For example, pollution changes how animals live. That is why humans need to be careful with the environment.

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Tyson Brown, National Geographic Society
National Geographic Society
Production Managers
Gina Borgia, National Geographic Society
Jeanna Sullivan, National Geographic Society
Program Specialists
Sarah Appleton, National Geographic Society, National Geographic Society
Margot Willis, National Geographic Society
Last Updated

October 19, 2023

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