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The World Asteroidea Database

The Asteroidea (also known as sea stars or starfish) are among the most diverse and familiar of the living Echinodermata, including over 1800 species from every ocean basin in the world, including the Atlantic, Indian, and Pacific as well as the Arctic and the Southern Ocean, inhabiting intertidal to 6000 m abyssal settings. Living asteroids are pentagonal to stellate (although some sphaerical forms are known) and have arms that are continuous with the disk. Two to four rows of tube feet are present. Most asteroids have five rays, but some can have as many as 50.

Taxonomic coverage of the database includes not only all “true” starfish taxa but also the enigmatic and controversial concentricycloids, which have been included based on the taxonomic classification of Mah (2006). Although identification of taxa with fossil members is indicated, most have not yet been included. Some fossil taxa may be entered in the future for completeness but fossil groups were not a primary objective for the WoRMS database.

The core of the World Asteroidea Database (WAD) is derived from the "Asteroid Names List" developed primarily by Ailsa M. Clark. However the WAD is complimented by numerous other echinoderm compendia (e.g., Clark & Downey's Starfishes of the Atlantic, Rowe & Gate's Zoological Catalogue of Australia, etc) and will eventually include all subsequent taxonomic changes and newly described taxa.

Please inform the editor, Christopher Mah, of any omissions, typos, or errors you encounter. I am also happy to review and discuss, other issues, such as synonymies, controversial taxonomic assignments, or broader classification questions and to initiate changes if they are warranted. All inquiries and discussion will be evaluated promptly but critically, and if deemed reasonable, included quickly into the database.

Further information on asteroids and echinoderms may be found at the authors’ blog: An academic profile of the authors can be found at:


Please cite the usage of the World Asteroidea Database if you utilize taxonomic information in your publications. This supports the academic contributions of the author and recognizes the contribution of this database to the greater community, which are important facets to the ongoing growth and development of taxonomic knowledge.

If data are extracted from this website for secondary analysis resulting in a publication, the website should be cited as follows:

  • Mah, C.L. (2019). World Asteroidea Database. Accessed at on 2019-10-20

This format is available at the bottom of every page in the Asteroidea database.

If any data constitutes a substantial proportion of the records used in secondary analyses (i.e. more than 25% of the data are derived from this source, or the data are essential to arrive at the conclusion of the analysis), the authors/managers of the database should be contacted. It may be useful to contact us directly in case there are additional data that may strengthen the analysis or there are features of the data that are important to consider but may not have been apparent from the metadata.

Image credits: Tosia australis courtesy of Kate Naughton, Pteraster obscurus by Heloise Chenelot. Glyphodiscus pentagonalis by Tom Schlager. All others by C. Mah.

Website and databases developed and hosted by VLIZ · Page generated 2019-10-20 GMT · contact: