Worms

Below are some worms you might find out about in the rocky intertidal or on the beaches. It is a limited set. I don’t flip rocks, dig around in the mussel beds, or otherwise do much disturbing—the things you would need to do to find many very cool worms. A few worms make above-ground appearances on the beaches, and I confess I’ve turned a spade or two of sand to uncover the occupant of a likely burrow entrance. Identifying worms is a challenge, but that’s part of the fun. (I can usually get close by using the field guides and online resources at this page’s bottom. When I can’t, it’s an enjoyable mystery.) So this is my catalog of the worms I’ve found, my photographic take, and a few words if I’ve thought of something that resonates with me and hasn’t been over-said. I use the organization followed by Lamb and Hanby (2005), common names are my choice, and all photos are from northern Oregon unless noted.

Let the worms be upon you!

The flatworm shown below is common, but pinning a credible ID on flatworms is challenging. Nevertheless, this one might be Notocomplana; if it is, it could be Notocomplana acticola, but there are look-alikes. I made a video of this one gliding along over its rock.

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The ribbon worms can be hard to identify; the green one below is no exception. It’s an expected find during low light and high moisture conditions in and around the mussel beds. Unfortunately, its color is not the best identification starting point. Still, without much else besides its size and habitat, it could be Emplectonema gracile. For other takes on green ribbon worms, it’s worth looking at the iNaturalist page on Emplectonema.

A green ribbon worm, possibly Emplectonema gracile, stretching over a barnacle encrusted rock surface.
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This intertidal predator might be the ribbon worm Amphiporus, something like Amphiporus formidabilis. Whatever it is, it’s got decent length and is abundant in and around the mussel beds. They’re active on the surface when light levels are low, and conditions are cool and moist. It’s worth taking a look at the iNaturalist page on Amphiporus. Here’s a video of this ribbon worm exploring the rocks at low tide.

 I’m impressed if it killed the isopod (it looks like Pentidotea)
Gliding around the rocks
Out and about under moist low light conditions
Bringing peristaltic moves to the hunt
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Orange ribbon worms are one of the brightest intertidal inhabitants. There is a decent chance those shown below are Tubulanus polymorphus, but I make no promises, as with the other ribbon worms. For more examples, see the iNaturalist page on Tubulanus polymorphus.

Tubulanus polymorphus, maybe | Central Oregon
No markings on the head, which is down to the left | Central Oregon
An individual can stretch from a few inches to over two feet | Central Oregon
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Here’s a good-sized, beautiful worm and a bit fragile down toward the tail. I’ve seen it a few times when it appeared on the surface of exposed sandy beaches early in the morning during low tides. The upper right image shows four jaws, a trait Glycera is known for, so that’s a good starting place for determining what it is. In that spirit, the INaturalist page on Glycera offers excellent browsing.

Close up of the head region on beach sand
Interesting stuff going on in the head region
Close up of head at an angle that looks into the jaw, somewhat, on beach sand
Peering into the jaws
The whole worm out on beach sand as I found it
Several inches long, pinkish, and a bit iridescent
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Nephtys
I’ve always thought the worms shown below are Nephtys californiensis, supposedly the most substantial goddess worm you’ll find on the clean sandy beaches of the outer coast. Still, like all things worm, there are alternatives. Healthy specimens are somewhat iridescent.

outline of goddess worm just under the surface of the sand. Here, the from hat of the worm is exposed.
You’ll sometimes see Nephtys traces in beach sand
burrow opening on the surface of rain-dimpled beach sand.
Nephtys burrow opening (confirmed by excavating)
Two finger bows, white and clear, with a good-sized Nephtys in the white one. Alos shown is my orange plastic spade and the now dug up burrow
Excavating Nephtys
Close up of the head and front part of the worm in my hand.
A fine Nephtys is a worm that will improve your day on the beach
Head and front part of the body on beach sand
The front part hides a good-sized proboscis
Dead goddess worm on sand. a few beach hoppers nibbling on the carcass.
Dead Nephtys are sought after by beach hoppers | Proboscis exposed here
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Nereis
This is probably Nereis vexillosa, the pile worm. They’re easy to find on the exposed shore crawling around in the mussel beds under low light conditions. I’ve also seen them out on the sand and in shallow sand-filled pools around spring and summer low tides. Kozloff describes the swarming behavior of ripe adults (females are redder posteriorly than males).

Here are examples from the rocks in and around mussel beds where Nereis can be reliably found when the timing of the tides permits.

Out and about in the early light of morning
Exploring rare open mussel bed space
Sensory palps give the head a horned look

Below are examples of worms out and about on the sand, just a short distance from rocks that support mussel beds.

It’s not just the big ones out on the surface
A ripe female?
Beach appearances seem to correspond somewhat with very low tides

Examples from shallow sand-filled pools.

Early morning in a shallow pool
Always curious
Doomed beauty

I wrote a few more words about this wonderful worm with a few other photos in Worm Watching.

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Dodecaceria
I’m pretty sure this colonial worm is Dodecaceria pacifica. If it is, you might know it as Dodecaceria fewkesi, but things change, and it now goes by Dodecaceria pacifica, at least in some circles. The first time I touched a mound, its rough hardness surprised me. Besides the worms within, the structures are composed of calcareous tubes embedded in cemented sand that can handle rough surf. Even so, most I’ve seen are set back slightly or located on indirect exposures. Colonies I’ve come across are mounted on vertical surfaces or, nearly so, either big walls or the edges of tidepools. Eroded colony fragments, sometimes called false brain coral, are a treat to find washed up on the beach or among the cobbles. I share a few more words and images in Construction on the Coast.

An exposed rock wall shared by a rich low intertidal community, including Dodecaceria. Surf and swash in the background in the lower left-hand portion of the scene.
Dodecaceria colony perched on a vertical wall
A rounded and much eroded fragment of a Dodecaceria colony washed up in the cobbles. The remnant is a bit bigger than most of the cobbles.
Found rattling around in the cobbles
A Dodecaceria colony at eh edge of a tidepool. Three giant green anemones and five or six purple urchins are also prominent. This scene is exposed by a quite low tide.
You can almost hear the crash of surf | Central Oregon
Close up on a mound to feature calcareous tubes and cemented sand. The mound is exposed by low tide.
Calcareous tubes and cemented sand
A rounded and much eroded fragment of a Dodecaceria colony washed up on a sandy beach. For scale, though not perfect, the fragment is a bit smaller than your fist.
Eroded fragments of Dodecaceria colonies are sometimes called false brain coral or fission worm rock
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I only know this worm from its clear tubes, which wash up abundantly on exposed sandy beaches. When folks in my orbit call them cellophane tube worms, they refer to Spiochaetopterus costarum. Here’s a short Seagrant/Hatfield Visitor Center piece on them with a photo of the tubes and a bit of cheerleading for cellophane tube worm as a common name. If that’s what they are, Lamb and Hanby use jointed three-section tubeworm, and the iNaturalist crowd goes with glassy tubeworm. Whatever way you lean, look for them in the fresh wrack.

Thin, clear tubes appear in the drift with terrestrial and human debris, on sand
Drifted tubes appear as short fragments
Small clump of drifted tubes on sand
Look for rings on clear tubes
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References

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.

Light, S. F., 2007. The Light & Smith Manual: Intertidal Invertebrates from Central California to Oregon. 4th ed., edited by J. T. Carlton. University of California Press.

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


Online Resources

Biodiversity of the Central Coast’s Marine Worms page

Friends of Netarts Bay WEBS Worms page. Accessed April 22, 2023.

Pacific Northwest Shell Club’s Worms page. Accessed April 22, 2023.

It’s worth scrolling down to worms in Common Sea Life of Southeastern Alaska: A field guide by Aaron Baldwin & Paul Norwood. Accessed April 22, 2023.

Cowles, D. (2004). Tubulanus polymorphus Renier, 1804. Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 11/03/2022.

Cowles, D. (2009). Nereis vexillosa Grube, 1851. Invertebrates of the Salish Sea. Rosario Beach Marine Laboratory. Accessed 11/04/2022.

iNaturalist’s pages on worms are full of good browsing material. Besides the links provided above, here are some others I looked at while preparing this page:

Notocomplana acticola

Fringed Filament Worm (Dodecaceria fewkesi)

Glassy Tubeworm (Spiochaetopterus costarum ssp. pottsi)


I updated this page on December 4, 2022