that looks like a basket start to me as well. we used to have one (quite some time ago). It wasted away slowly unfortunately. That's how we found out that basket stars (like many other critters in the ocean) often have a VERY SPACIFIC diets. I don't presume to know what species you have, but I would urge you do your homework and see if you can replicate it's diet. otherwise, yours may suffer the same fate as ours did. BEST OF LUCK!