Sponges

Below you’ll see examples of sponges I’ve encountered on the surf-swept shores of the exposed Oregon coast. The photos are from northern Oregon unless noted. Organization-wise, I loosely follow Lamb and Hanby (2005). If I use common names, they’re my choice. Experts cover these examples and many more in the books, field guides, and identification resources listed at the bottom of the page, but all of them tell us identification is going to be tough for non-experts; phenotypic variation and lookalikes occur, and microscopic examination of the spicules may be needed. Thus, any identifications I give are tentative, even at the genus level, and open to interpretation.

Let’s enjoy the sponges!


Isodictya

I encountered this drifted beauty among a mass sea wrack. It’s a tentative identification, but if it is Isodictya, it could be Isodictya rigida, the orange finger sponge. Whatever you make it out to be, the common name is a good fit for this specimen.

A drifted orange finger sponge Isodictya rigida resting in a mass of sea wrack.
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Breadcrumb sponge

My examples closely resemble Halichondria panicea, but I say that not really knowing how many, if any, lookalikes might be around to complicate things.

Breadcrumb sponge Halichondria (Halichondria) panicea on a rock wall with gooseneck barnacles, thatched barnacles, and a giant green anemone.

In the examples featured in this entry, you’ll see oscula concentrated along ridglines.

Breadcrumb sponge Halichondria (Halichondria) panicea on a rock wall with a small Pisaster, anemones, small barnacles, and California mussels.
Breadcrumb sponge Halichondria (Halichondria) panicea on a rock wall with a s few Pisaster arms extending onto the scene.
Breadcrumb sponge Halichondria (Halichondria) panicea on a rock wall with Corallina and Bossiella. In the background, giant green anemones.


I can confirm Monterey dorids Doris montereyensis rank among breadcrumb sponge’s nudibranch predators.

A Monterey dorid Doris montereyensis apparently eating it's way through a patch of breadcrumb sponge Halichondria (Halichondria) panicea.
A Monterey dorid Doris montereyensis apparently eating it's way through a patch of breadcrumb sponge Halichondria (Halichondria) panicea.
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Purple encrusting sponge

The examples shown below closely resemble Haliclona cinerea (formerly Haliclona permollis) illustrated in the resources shown at the bottom of this page.

A good-sized patch of purple encrusting sponge Haliclona cinerea (or something very like it) on a vertical and overhanging rock wall.
From the central Oregon Shore
Purple encrusting sponge Haliclona cinerea (or something very like it) on a vertical rock wall. A few giant green anemones, some Ulva, and an inscrutable red seaweed share the scene.
From the central Oregon shore
Closeup of a patch of purple encrusting sponge Haliclona cinerea (or something very like it), highlighting the oscula.
Trademark well-spaced oscula | Central Oregon


The nudibranch Diaulula odonoghuei, as widely reported, feeds on the purple encrusting sponge and will place its egg ribbon rosettes in its midst as well. (The pair of images below are from the central Oregon shore.)

A pair of nudibranchs Diaulula odonoghuei with a recently-laid egg ribbon rosette in a small open space amidst a patch of purple encrusting sponge Haliclona cinerea (or something very like it) on a vertical rock face.
Two nudibranchs Diaulula odonoghuei in recently-eaten open spaces in a patch of purple encrusting sponge Haliclona cinerea (or something very like it) on a vertical rock face.


I guess this is probably a case of bleaching or worse, but it is interesting because the question of color is inevitable for a sponge named after its color.

From the central Oregon shore


Either way, it’s not too uncommon to find tan-colored sponges with a superficial morphology similar to the typically-colored purple encrusting sponge.

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Red encrusting sponge

Recognizing the well of red sponge identification is fathomless for most of us, the examples below show a range of superficial red encrusting sponge looks, their backgrounds, and their mid- and low intertidal associates.

A bright red encrusting sponge surrounded by aggregating anemones, exposed at low tide.
A bright red encrusting sponge exposed at low tide.
A bright red encrusting sponge surrounded by aggregating anemones, exposed at low tide
Closeup of a red encrusting sponge exposed at low tide.
A red encrusting sponge mostly surrounded by purple encrusting sponge Haliclona.
A red encrusting sponge surrounded by crustose corallines.
A red encrusting sponge surrounded by giant green anemones and a variety of seaweeds.
A red encrusting sponge surrounded by lots of tiny barnacles, a pink-tipped green anemone, and some inscrutable red blades.
A patch of red encrusting sponge on a vertical rock where it meets the sand.


The examples below celebrate the oft-described connection between the red encrusting sponge Clathria pennata and the nudibranch Rostanga pulchra.

A red encrusting sponge, maybe Clathria pennata, hosts a pair of red sponge nudibranchs Rostanga pulchra and their egg ribbon(s).
A red encrusting sponge, maybe Clathria pennata, hosts a pair of red sponge nudibranchs Rostanga pulchra and three egg ribbons.
A red encrusting sponge, maybe Clathria pennata, hosts a red sponge nudibranch Rostanga pulchra.
A red encrusting sponge, maybe Clathria pennata, hosts a red sponge nudibranch Rostanga pulchra.
A red encrusting sponge, maybe Clathria pennata, hosts at least one red sponge nudibranch Rostanga pulchra and two egg ribbons.
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From the drift line

This velvety beauty washed up in a mass of drifted seaweed.

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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

Friends of Netarts Bay WEBS Sponges page. Accessed January 6, 2026.

Stanford | SeaNet’s Demospongia page. Accessed January 6, 2026.

World Porifera Database. Accessed January 6, 2026.


I updated this page on January 6, 2026