A list of the region's endemic echinoderms is here.​

​

California is moderately diverse in echinoderms. Within North America, the California Current has 290 species, twice as many as there are in the Northeast US and Arctic, but few compared to the 500+ found in the Gulf of Mexico. 

​

Notable endemics are the Bay Area six-rayed star (Leptasterias pusilla), the California sand star (Astropecten verilli), and the red sea cucumbers (Lissothurea nutriens and Pachythyone rubra). 

​

Although not endemic, the ochre star (Pisaster ochraceus) is ubiquitous in California, and notable for being the type used by Paine to describe the keystone species phenomenon. The well-known and beloved bat star (Asterina miniata) is particularly common in California's waters. The world's largest seastar (at least by mass), the giant sunflower star (Pycnopodia helianthoides) was once common in our region. In 2013, an epidemic of seastar wasting disease broke out on the Pacific Coast, reducing numbers of sea stars throughout California and all but extirpating the giant sunflower star from California and Oregon. 

​