This seems to be a type of linckia species. I bought a Two Oceans marine ID book a short while back, and they describe the linckia as having long slender cylinderical arms (as the one in the pics above).
BUT, Sean, if this came from 30 kilometers in the sea, can we safely presume that this would be a "deep-sea star-fish"? What would such a star eat? I think that my linckia eats "detritus build-up" on the rocks, as well as the algae film that gets created on the rocks. My linckia seems to be light-shy, and only really comes out in the dark (or when only my actinics are on). My linckia is flourishing (seemingly) in my tank, as it has grown about a centimetre and a half since I got it...
So, I don't think this star-fish would do well in a "completely nutrient-less" (read: SPS) tank..... It would most likely starve and die a slow death (especially seeing as it is so big, it would need a LOT of food).