Sea Anemones

Below are examples of anemones I’ve seen living on Oregon’s exposed rocky intertidal. Compared to what you could find, it’s a limited sample, just the most obvious common forms I’ve been lucky enough to photograph on the shores I visit. The photos are from northern Oregon unless noted. Organization-wise, I follow Lamb and Hanby (2005). I refer to WoRMS for species names, and if I use common names, they’re my choice. The books, field guides, and identification resources listed at the bottom of the page cover the anemones shown below and many more.

Let there be anemones!


Metridium senile, short plumose anemone
Underwater, with its tentacles extended, it’s a beautiful anemone. But, unfortunately, I only experience that beauty rarely on exposed northern Oregon shores. Those in the photo below found favorable conditions on a protected overhanging rock face.

A profusion of Metridium senile exposed by low tide. A large Pisaster, giant green anemones, and aggregating anemones are also present.
Anemone expo
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I think the anemones shown in the set below are Urticina grebelnyi. Still, I can’t claim much experience with Urticina nor much in the way of anemone identification skills, so there is some uncertainty. Either way, this good-sized anemone is a low intertidal beauty.

An olive green Urticina (probably), with just a few red streaks, hangs down beneath a ledge.
At home hanging down | Central Oregon
Early sun shines on an anemone (with mottled red streaks) hanging down under a ledge.
An overhang doesn’t protect against early morning sunshine | Central Oregon
Anemone with a primarily red column with olive green blotches (tentacles withdrawn), hides among Ulva. (Ulva blades have been moved to expose the anemone.)
It’s easy to understand the common name, painted anemone | Orcas Island
A primarily red Uticina (probably) with some olive on the oral end of the column.
Color variation is infinite | Central Oregon
Urticina (probably) hanging down, tentacles retracted. The column is coppery olive-green with faint traces of red.
Rarely encountered intertidally outside protected or at least semi-protected places | Central Oregon
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Anthopleura xanthogrammica, giant green anemone Giant greens have been honored with one of the best scientific names, and with their accessibility, size, and beauty, they’re a tidepool superstar. To see an intimate view of the oral disk, click here.

A quiet tidepool full of giant greens and some up on the pool walls too.
Anthopleura xanthogrammica in a low tide pool
Medium close up, about six decent-sized giant greens fill the frame.
The ever-popular giant green
Intimate view of the oral disc and tentacles of two giant green anemones.
A. xanthogrammica is one of the larger, gaudier tide pool invertebrates
Intimate view of several giant greens hanging out in the corner of a low tidepool.
Once they settle, giant greens aren’t apt to move around
An intimate view of a single exposed giant green hanging down a wall at low tide. Tentacles retracted.
Giant greens can live for years
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Anthopleura elegantissima
This anemone carries around a lot of common names, the most familiar of which, at least to me, are aggregating and pink-tipped green. One nice thing about them is you don’t have to wait for a super low tide to find them. Instead, they’re abundant on mid-intertidal rocks where it’s worth spending a few moments looking for lines of separation between adjacent aggregations. Anthopleura elegnatissima is featured in Aggregating Anemones Handle the Sand, and Anthopleura elegantissima Lives Up to All Its Common Names.

Anthopleura elegantissima on the edge of a tide pool. A large Pisaster and a few giant green anemones are also present.
The small, densely-packed anemones are pink-tipped greens, Anthopleura elegantissima
Close in on a couple of dozen anemones (Anthopleura elegantissima) exposed by the low tide on a vertical face. Some columns are extended a bit, but they all have retracted tentacles.
Exposed
A thin band of space between two adjacent aggregations.
You may notice some open ground between aggregations
A half dozen closely packed A. elegantissima in a rocky tide clear tidepool. They've extended their tentacles.
When you encounter A. elegantissima, there’s likely to be a crowd
Lineup of three Anthopleura elegantissima, tentacles extended, in a clear, shallow tidepool.
For intertidal beauty, A. elegantissima delivers
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Anthopleura artemisia, moonglow anemone 
On the exposed outer coast, you’ll almost always find moonglows where sand meets rock.

Anthopleura artemisia extending its tentacles from a hole in a clear tidepool.
Peeking out from cover
Anthopleura artemisia in a shallow, sand-filled tidepool.
The tentacles frequently have white bands
Anthopleura artemisia extending its orange tentacles from the sand in a shallow, clear pool.
There is quite a bit of color variation
Closeup on a lone moonglow anemone, greenish and a bit luminescent.
Monnglows are a bit luminescent | Galiano Island
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References

Gotshall, D. W. 2005. Guide to Marine Invertebrates, Alaska to Baja California 2nd Edition (Revised). Shoreline Press.

Harbo, R. M. 2011. Whelks to Whales: Coastal Marine Life of the Pacific Northwest. 2nd ed. Harbour Publishing Co.

Kozloff, E. N. 1993. Seashore Life of the Northern Pacific Coast. 3rd ed. University of Washington Press.

Lamb, A. and B. P. Hanby. 2005. Marine Life of the Pacific Northwest. Harbour Publishing.

Sept. J. D. 2019. The New Beachcomber’s Guide to the Pacific Northwest. Harbour Publishing.


Online Resources

Biodiversity of the Central Coast’s Cnidarians and Ctenophores page. Accessed 01/19/2023.

Friends of Netarts Bay WEBS Sea Anemonies, Hydroides, Jellies (Phylum Cnideria) page. Accessed 01/19/2023.

It’s worth scrolling down to anemones in Common Sea Life of Southeastern Alaska: A field guide by Aaron Baldwin & Paul Norwood. Accessed 01/19/2023.


Cowles, D. (2004, as edited). Anthopleura artemisia (Pickering in Dana, 1848). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 01/19/2023.

Cowles, D. (2005). Metridium senile subsp. fimbriatum (Verrill, 1865) [Harbo, 1999 says Linnaeus, 1767]. Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 01/19/2023.

Cowles, D. (2005). Urticina crassicornis (O. F. Muller, 1776). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 01/19/2023.

Piazzola, C.D. and T.C. Hiebert. 2015. Metridium senile. In: Oregon Estuarine Invertebrates: Rudys’ Illustrated Guide to Common Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biol- ogy, Charleston, OR. Accessed 01/20/2023. Accessed 01/19/2023.

Piazzola, C.D. and T.C. Hiebert. 2015. Anthopleura artemisia. In: Oregon Estuarine Invertebrates: Rudys’ Illustrated Guide to Com- mon Species, 3rd ed. T.C. Hiebert, B.A. Butler and A.L. Shanks (eds.). University of Oregon Libraries and Oregon Institute of Marine Biology, Charleston, OR. Accessed 01/22/2023.

White, B. (2002 as edited). Anthopleura xanthogrammica, Brandt (1835). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 01/19/2023.

White, B. (2002 as edited). Anthopleura elegantissima (Brandt, 1835). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 01/19/2023.


I updated this page January 22, 2023