Keep Your Friends Close, BUT! … Your Anemones CLOSER!


Sure, there were lots of reasons for Nemo to bust out of that Dentist office aquarium. In our version of the story, it was mostly because he couldn’t bear to live outside of his anemone.

Nemo is a clownfish, also known as anemonefish because these fish make their homes in anemones. Of over 1,000 anemone species worldwide, only 10 coexists with tropical clownfish. The fish and its anemone are in a symbiotic relationship – this means that the fish benefits from the anemone and vice versa.

Clownfish are the only fish capable of living in an anemone without getting stung by its tentacles. Like their relatives, jellies and corals, anemones have stinging cells on their tentacles. How do the clownfish escape being stung? They have a slimy mucus covering that protects them from the stinging tentacles. Scientists know this because they took clownfish, wiped off the covering, and found that the fish would get stung when they were returned to their home anemone.

The anemone gives the clownfish protection from predators and the fish gets food when it cleans away leftover anemone prey. The anemone benefits when the fish chases away anemone predators. And the fish gives the anemone nutrients in its poop and dropped food as well as good water circulation as it fans its’ fins while swimming.

Oh give me a home, where the anemones roam…

Clownfish aren’t the only organisms that live with anemones. On some Caribbean reefs, the large corkscrew anemone hosts a variety of different shrimps and crabs including cleaner shrimp like the red pistol shrimp. Scientists know that pistol shrimps and anemones trade several resources including nitrogen, which is a limited resource in reef ecosystems. Also, the shrimp eats anemone mucus and gets protection by the anemone’s stinging cells. The shrimp protects the anemone from predators, pinching and snapping them back using their modified claw.

Read more about anemonefish and anemones:

From the Monterey Bay Aquarium great information about Anemonefish
From Haiki Coastal Science and Societies Magazine, this is good article about corals with photos
More information and a poem about clownfish
Photos of anemones, many with clownfish
Photos and video of one of the most common clownfish and anemones
Photos of pistol shrimp in an anemone
Snapping shrimp defends anemone