I almost tossed the photo, but then I looked at it more closely.
|Pisaster ochraceus. The arms are as usual; hard, knobbly skin. But around the central portion, the skin is puffy and either lined or ridged. (It helps to click for the full size photo.)|
|Zooming in on the original. I think those are curly ridges.|
I'd never noticed skin like this on a sea star before. I looked up a bunch of my old photos; none of them are puffy. On the web, I found one with the wrinkles, a close-up of the skin taken in 2011. By the accompanying photos, I think it was somewhere on the Washington-BC coastline; the photographer doesn't say.
Now I find that I must head out again next low tide, carrying a hand lens to examine every sea star I can find.
By the way, while you're here, notice the unusual green wrists of the purple shore crab nestled beside the star.
(I've decided that I should really be recording the exact location of the intertidal critters I photograph; from one beach to the next, the communities are so different. This was taken almost exactly on the 50th parallel north.)