It’s pretty hard not to encounter Anemonefish when scuba diving or snorkeling along most tropical coral reefs. They are one of the most colorful and distinctive fish in the ocean.

Lifespan

Anemonefish belong to a subfamily of Damselfish. There are about 30 species of Anemonefish. They have a lifespan of 3 to 6 years and grow to a maximum length between 6 to 7 inches. It is rare to find Anemonefish away from their hosts and therefore named for their association with Sea Anemones.

Symbiotic Relationship

These tiny and energetic fish have developed a unique and symbiotic relationship with Sea Anemones. Anemonefish are one of the only creatures that can withstand the toxins of the Anemones. A sting from an Anemone can be fatal to some fish.

Two theories on how Anemonefish can survive the toxins:

1. Anemonefish have a coating of mucus that provides protection from toxins or sends a signal to the Anemone that the fish is not food or predator.
2. Coevolution may have allowed the fish to evolve an immunity to the toxins of the Anemone.

Both the Anemonefish and Sea Anemone help protect each other from predators. For example, the Anemonefish helps clean the Anemone by eating parasites that might attach to the Anemone. And the Anenonefish is able to seek shelter among the Anemone’s tentacles. Also, the Anemonefish will eat undigested food that the Anemone missed.

Anemonefish live in small groups with a single large dominant female. All Anemonefish are born male. The fish are hermaphrodites which means that they can change sex. Typically when the female dies, the largest and most dominant male will change sex and take the female’s place.

Diet

Anemonefish diet consists mainly of algae, zooplankton, and small crustaceans.

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I captured the video above on a Panasonic GH5. My camera set can be found here.