Sand Sifting Star - Astropecten polycanthus

Acording to the Livequaria.com description, Astropecten polycanthus
do not have suction cups so they cannot climb glass/rocks. I am not
sure if Liveaquaria is right or wrong, but my star has suction cups and
does climb glass. Maybe I have something different, not Astropecten
polycanthus? I am currently trying to identify mine because since I put
it into the tank the substrate is dead-clean. No benthic animals whatsoever.
And before putting it in I have quite a live sand with a lot of miniature
brittle stars, copepods and other live forms. Now it is dead-dead.
I tried to feed my star recently to prevent it from eating critters form
the bottom of the tank but it just ignores completely chunk of shrimp meat
put underneath it and just walks away. Maybe not hungry anymore?
Or maybe not guily of this carnivore job?
If you can - please help me identify - you will find pictures he
www.polbox.com/p/pszemol/english.html - click on Sand Sifting Star.
If you have good marine invertebrate atlas, please check if Astropecten
polycanthus has suction cups or not... and what does it eat for real...
Thanks!