University of Oregon

Oregon Estuarine Invertebrates, Third Edition

This is an open-access resource originally created by Jerry and Lynn Rudy. The third edition is edited by Terra C. Hiebert, Barbara A. Butler and Alan L. Shanks.

To submit corrections, questions or request to become editor of a species profile please email



Cnidaria (Sea anemones and allies)

Nemertea (Ribbon worms)

Annelida (Segmented worms)

Sipuncula (Peanut worms)

Arthropoda (Crustacea)

Mollusca (Mussels, clams, snails, and slugs)

Phoronida (Horseshoe worms)

Echinodermata (Sea stars and sea urchins)

Chordata (Tunicates)


Species A-Z


Lynn and Paul Rudy first published Oregon Estuarine Invertebrates: An Illustrated Guide to the Common and Important Invertebrate Animals (OEI) in 1983. It contained 110 descriptions with a single page of text facing Lynn’s amazing illustration of each species. As they stated in their introduction, this work was intended to be updated as new information became available. It was not intended to be a key but rather a guide for students and researchers in Oregon, Washington, and northern California. They created a 30-species supplement in the early 1980s, but it was unfortunately lost for a time by their USFWS publishing partner. It turned up years later upon his retirement and subsequent office cleaning.

In retirement, Lynn and Paul gave permission to OIMB staff to continue updating their publication. In 2005, the 1983 edition of OEI was digitized and made freely available in University of Oregon’s institutional repository (Scholar’s Bank): Several years later the missing species descriptions were returned to OIMB and incorporated into the existing, and digitized work. Two OIMB graduate students digitized each of the 140 illustrations and replaced the Leroy Lettering Set labels with computer generated text. The bibliographies were also fleshed out, giving full citations for each work and pointing to individual chapters within cited monographs. We also included updated taxonomic names where necessary and published this in Scholars’ Bank as the Second Edition of OEI: To facilitate future updates, each species description was also published as a separate chapter, each containing footnotes directing readers to send suggested corrections or updates to OIMB staff.

While the Second Edition of OEI contained additional species descriptions, fuller bibliographies, and re-labeled illustrations, there was no additional content aside from relabeling with current taxonomic names. As part of a Winter 2014 Graduate Seminar, OIMB students updated 18 of the chapters. Two students authored new species descriptions and one was able to split a basic description of Littorina sp. into individual descriptions for Littorina plena and Littorina scutulata. At this point, OEI truly became a collaboration among OIMB students and faculty. The greatest step forward occurred in Fall 2014 when the University of Oregon Libraries provided funding for Terra C. Hiebert to incorporate new information from the intervening 30 years in this now open-access publication. Clara D. Piazzola helped with the eight cnidarian species and Barb Butler and Alan Shanks served as editors for the entire volume. Over this 1.5-year-period, Terra standardized the edits made by her fellow students; revised 126 of the (now) 142 descriptions; and when necessary added a “taxonomy” section at the beginning of description to clarify changes that have occurred through the years. These species descriptions are available as individual chapters within Scholars’ Bank and in the 2016 the full Third Edition was published under the updated subtitle of Oregon Estuarine Invertebrates: Rudy’s Illustrated Guide to Common Species ( Future OIMB Invertebrate Zoology students will update the remaining species descriptions, continuing the collaborative tradition started by the Rudys.

We have added an index to common names, as well as names previously used in this guide, and include a map of the Coos Bay area to help students locate sampling sites mentioned in the text. An online index points to all of the species descriptions in Scholars’ Bank: We consider the publication date for the entire volume to be 2016, but have noted when an individual species description was updated in 2014 or 2015. Species are grouped by phyla, then grouped by order or class, then alphabetically by family and finally alphabetically by genus. We also include an overall A-Z list by species name for those not familiar with invertebrate nomenclature.

A number of students have assisted with this publication. Many thanks to Megan Grupe (née Copley) and Sara Okum (née Williams) for their work on the illustration labels and to Heidi Harris and Jennifer Schmitt for their work on the bibliography and text formatting. Unless denoted by the presence of a co-author, all species descriptions are by Terra C. Hiebert. Unless otherwise noted, all all illustrations are the work of Lynn Rudy. While the content has been updated, we have kept the tried-and-true format that Lynn and Paul established for OEI, in particular the “Possible Misidentificaton” section that is so useful to students. As you scan the bibliographies you will note our reliance on a number of important works, including The Light and Smith Manual, and James T. Carlton was our primary source for any taxonomic questions.

A number  of OIMB alumni have contributed funds to underwrite the cost of future updates to OEI as well as covering the cost of Rite-in-the-Rain paper and large-format binders to make multiple copies of OEI available in all OIMB teaching laboratories.

Suggested citation format for OEI chapters:

Hiebert, T.C. and L. Rasmusson. 2016. Cancer magister. 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 Biology, Charleston, OR.

We dedicate this work to the Rudys for all they have done for OIMB and its students.