Giant Green Anemone

Anthopleura xanthogrammica

Giant Green Anemone

Anthopleura xanthogrammica

Other Common Names
Green surf anemones, solitary green anemone

Rocky Coast

Other Common Names

Green surf anemones, solitary green anemone

At the Aquarium

Rocky Coast

Appearance

As their name suggests, these anemones are relatively large, with a diameter of 7-12 in. and about 12 in. tall. On the largest specimens, tentacles can reach as long as 10 in. The column has many small sticky tubercles. The anemones get much of their green coloring from photosynthetic symbionts that live in their body tissue. They have both microalgae (zoochlorellae) and dinoflagellates (zooxanthellae) that provide them with some nutrients and contribute to their green coloration.

Habitat

Found in tide pools and subtidally on rock walls and surge channels of exposed rocky shores, associated with california mussels; also found on pilings in bays, to depths of at least 50 ft; juveniles can be found directly within mussel beds.

Diet

California mussels are a favorite, but these opportunistic carnivores will also eat crabs, sea urchins, worms, and small fish.

Life History

Giant green anemones are only able to reproduce sexually.

Sexual maturity is reached at 5 to 10 years of age. Reproduce by broadcast spawning annually.

An individual under human care lived for 80 years and it is thought that this species might reach 150 years or longer.

IUCN Status

Not Evaluated

Ecosystem & Cultural Importance

Giant green anemones have a role in many parts of the food web as both predator and prey. They often settle near mussel beds so that they are close to a food source. They also eat crabs, sea urchins, and small fish. This anemone’s column and tentacles are eaten by a variety of predators including sea spiders, crabs, sea stars, and nudibranchs.

Alaska to Panama to Hudson Bay, Canada and over to the Eastern Coast of Russia.

These anemones are plentiful in tide pools on the Oregon coast!

Zoochlorellae, a microalgae, and zooxanthellae, a dinoflagellate, live in the tissues of the giant green anemone. These photosynthetic organisms provide the anemone with food and much of its color in exchange for a home.

Citations & Other Resources

Animal Diversity Website: https://animaldiversity.org/accounts/Anthopleura_xanthogrammica/
Monterey Bay Aquarium website: https://www.montereybayaquarium.org/animals/animals-a-to-z/giant-green-anemone
National Marine Sanctuary Foundation website: https://marinesanctuary.org/blog/sea-wonder-giant-green-anemone/

Giant Green Anemone

Giant Green Anemone

Other Common Names

At the Aquarium

Appearance

Habitat

Diet

Life History

IUCN Status

Ecosystem & Cultural Importance

Citations & Other Resources

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