Zoroaster Sea Stars

Zoroaster Sea Stars (Zoroaster sp.)

A zoroasterid sea star at Axial Seamount, likely Zoroaster spinulosus. Photo credit: NSF-OOI/UW/CSSF; Dive R1721; V14.

We have encountered several species of Zoroaster sea stars, a widespread genus of mostly deep-water echinoderms, at both Axial Seamount and Oregon coast sites. These sea stars, sometimes referred to as "rattail stars" (possibly because their long, tapering arms have a resemblance to Grenadier aka rattail fish tails) have five long, skinny arms and very small central discs, giving them a very distinctive appearance. The ones we have observed near OOI infrastructure are frequently pale yellow or white in coloration, sometimes with spiny projections on the aboral surface.