Starfishes

Below are examples of a few starfishes that I’ve encountered on Oregon’s wave-swept rocky shores. The photos are from northern Oregon unless noted. My organization loosely follows Lamb and Hanby (2005). Common names, if I use them, are my choice. Experts cover these starfishes and many more in the books, field guides, and other resources listed at the bottom of the page.

It’s time for sea stars!


Pisaster ochraceus Ochre star

No tidepool invertebrate on northeastern Pacific shores evokes more human fascination and connection. When Pisaster’s doing well, all seems right with the world.

In the foreground, two ochre stars Pisaster ochraceus exposed by low tide (surrounded by kelp). The view is out to the surf zone on a gray, misty day.
Five ochre stars Pisaster ochraceus, tightly bunched up against the surfgrass.
Five ochre stars Pisaster ochraceus, bunched on a vertical rock surface with a variety of seaweeds draped down.


They’ll pose for you

Closeup on the central portion and three arms of an ochre star Pisaster ochraceus on a vertical rock surface alone with portions of three giant green anemones, a crustose coralline, and a tuft of thin red blades.


At home at the base of the Mussel Beds

I like to look for Pisaster ochraceus along the base of the mussel beds. That lower margin is the best place I’ve found to pause and appreciate Pisaster for the part it plays.

In the foreground, a large orange ochre star Pisaster ochraceus at the base of the mussel bed (exposed by low tide). The view is along the exposed mussel bed. In the distance you get a sense of zonation.


Pisaster postures

Speaking of the part Pisaster ochraceus plays—one of the parts, anyhow—you can probably figure out what these postures illustrate.

Closeup of a lone ochre star Pisaster ochraceus on an overhanging rock wall with its arms draped over a mussel.
Closeup of an ochre star Pisaster ochraceus at the base of the mussel bed with its arms draped over a mussel. The view is out across a wide exposed beach at low tide. Clear early morning sky with a little color on the horizon.
From the central Oregon shore
Closeup of a lone ochre star Pisaster ochraceus on an overhanging rock wall with its arms draped over a mussel.
An ochre star Pisaster ochraceus at the base of the mussel bed with its arms draped over a mussel. In the distance, sand, rocks, and maritime forest.
Closeup of an ochre star Pisaster ochraceus at the base of the mussel bed with its arms draped over a mussel.
Closeup of an ochre star Pisaster ochraceus at the base of the mussel bed with its arms draped over a mussel.


Lower, below the mussel beds—if there are places where rock meets sand—ochre stars will congregate along that sand-scoured boundary.

About 25 ochre stars Pisaster ochraceus closely bunched along the sand/rock interface.
Dozens of ochre stars Pisaster ochraceus closely bunched along the sand/rock interface.
Closeup of about eight ochre stars Pisaster ochraceus closely bunched along the sand/rock interface along with a few giant green anemones.
Six ochre stars Pisaster ochraceus closely bunched along the sand/rock interface.
Six ochre stars Pisaster ochraceus closely bunched along the sand/rock interface.


The range of colors exhibited by Pisaster ochraceus is remarkable. Among the brightest creatures inhabiting the shore are the orange stars (as seen in some of the images in this entry) are standouts. Electric indigo, when you’re lucky enough to find that form, is an eye-catcher too.

Closeup of six ochre stars Pisaster ochraceus bunched together at the base of the mussel bed exhibit a range of colors.


The cutest babes

A tiny ochre star Pisaster ochraceus perched on a giant barnacle Balanus nubilus.
“I’m going to eat you!”
Intimate scene of two baby ochre stars Pisaster ochraceus on two adjacent mussels within the bed.
Closeup of a baby ochre star Pisaster ochraceus on a rock.
Closeup of a baby ochre star Pisaster ochraceus next to a portion of the arm of a large adult, both on a sand-scoured rock.
A closeup of a baby ochre star Pisaster ochraceus next to a portion of a probable adult tucked back in a recess among the mussels. A giant green anemone shares the scene.


Down on the rock/sand boundary there are so many babies around this larger star.

Closeup of a large ochre star Pisaster ochraceus surrounded by twenty or more babies on a sand-scoured rock.
***


Evasterias troschelii Mottled Star

It’s unusual for me to come across large mottled stars out in the open, but this one was easy to spot from a distance. I just love how its coloration plays with those of the Bossiella and those inscrutable red blades.

A good-sized mottled star Evasterias troschelii nestled among Bossiella and red blades.


Babes now, they don’t hesitate to spend their time more or less out in the open atop low-lying, sand-scoured rocks.

A small mottled star Evasterias troschelii on a low sand-scoured rock. 15 cm rule for scale.
A small mottled star Evasterias troschelii on a low sand-scoured rock. 15 cm rule for scale.
A small mottled star Evasterias troschelii on a low rock. A crustose coralline shares the scene. 15 cm rule for scale.
A small mottled star Evasterias troschelii on a low rock. A crustose coralline and some other small red seaweeds share the scene. 15 cm rule for scale.


Comparative shot—that’s Pisaster ochraceus on the right

A small mottled star Evasterias troschelii nestled in a bed of sand-scoured false kelp Phaeostrophion irregulare next to a small ochre star Pisaster ochraceus on a low sand-scoured rock. 15 cm rule for scale.


Just a couple more babes

A small mottled star Evasterias troschelii in a protected niche on a low rock. A crustose coralline shares the scene.
A small mottled star Evasterias troschelii in a protected niche on a low rock. A crustose coralline shares the scene.
***


Leptasterias Six-Rayed Stars

Rock wall inhabited by a six-rayed star Leptasterias, some small barnacles, and a few widely-spaced giant green anemones.


Leptasterias is a collection of species complexes. (I think, with some uncertainty, the examples below represent Leptasterias; I know they all have six rays!)

Six-rayed star Leptasterias on a vertical wall, associating with barnacles, a nudibranch, Pollicipes, and Pisaster.
Six-rayed star Leptasterias (I think) in a sand-filled pool with a sculpin and some pink-tipped and giant green anemones.
I didn’t even notice the sculpin
Six rayed star Leptasterias on a coralline crust.
Six-rayed star Leptasterias on a sand-scoured rock rock among coralline crusts and amemones.
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Pycnopodia helianthoides Sunflower Star

I haven’t encountered these predators in the wild intertidal since April 2013.

Sunflower star Pycnopodia helianthoides in a shallow sand filled pool. Rock and seaweeds behind.
Sunflower star Pycnopodia helianthoides in a shallow sand filled pool. Rock and seaweeds behind.
***


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.

Lambert, P. 2000. Sea Stars of British Columbia, Southeast Alaska and Puget Sound. UBC Press. 

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


Online Resources

Friends of Netarts Bay WEBS Echinoderms page. Accessed September 6, 2025.

It’s worth scrolling down to Asterozoa (Brittle stars and sea stars), page 145, in: Common Sea Life of Southeastern Alaska: A field guide by Aaron Baldwin & Paul Norwood. Accessed September 6, 2025.

Check out Neil McDaniels’ Sea Stars of the Pacific Northwest. Accessed September 6, 2025

Species Accounts

Cowles, D. (2005). Evasterias troschelii (Stimpson, 1862). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed September 6, 2025.

Cowles, D. (2005). Pycnopodia helianthoides (Brandt, 1835). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed August 5, 2025.

McFadden, M. (2002 as edited). Leptasterias aequalis (Stimpson, 1862). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed September 6, 2025.

McFadden, M. (2002 as edited). Leptasterias hexactis (Stimpson, 1862). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed September 6, 2025.

McFadden, M. (2002 as edited). Pisaster ochraceus (Brandt, 1835). Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed September 6, 2025.

I updated this page on September 6, 2025