You’ve missed out if you haven’t spent time gazing down into a tidepool, patiently scanning it for nudibranchs. Below are examples of nudibranchs you are likely to run across on Oregon’s exposed rocky shores if you spend some time trying. My organization follows Lamb and Hanby (2005). Common names are my choice. I refer to WoRMS for scientific names, and I learn a ton by browsing the natural history riches in Kozloff (1993). The Biodiversity of the Central Coast’s Molluscs page contains excellent information about the nudibranchs shown below and more. The books, field guides, and identification resources listed at the bottom of the page also cover them.

Doris montereyensis

Diaulula odonoghuei
The Salish Sea Invertebrates web site has a page on Diaulula odonoghuei that’s full of information on leopard dorids.

Acanthodoris nanaimoensis

Rostanga pulchra, red sponge nudibranch

Dirona albolineata, white-lined dirona

Dirona, the explorer


Antiopella fusca

Hermissenda crassicornis, thick-horned nudibranch
Thick-horns have one of the best scientific names. And, on a personal note, it’s the first nudibranch I discovered in the wild.


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. 2009. The Beachcomber’s Guide to Seashore Life in the Pacific Northwest. Revised ed. Harbour Publishing.

Online Resources

Biodiversity of the Central Coast’s molluscs page is full of great information on Pacific Northwest nudibranchs.

Pacific Northwest Shell Club’s Nudibranch page

I consulted several iNaturalist pages while preparing this page, including:

Monterey Doris (Doris montereyensis)

California Sea Slugs – Nudibranchs

Spotted Leopard Dorid (Diaulula odonoghuei)

Thick-horned Nudibranch (Hermissenda crassicornis)

White-Lined Dirona (Dirona albolineata)

This page was updated on April 22, 2022