Ophiura....Can you ID??

[yosemite sam]

I was looking in my tank last night, and noticed this little guy feeding. At first I thought it was algae, but after watching it for a while, it started to move. It has I think 5 arms, each of which can coil and uncoil independently. I asked some friends, and we've come up with either a basketstar or a cucumber. The problem is that it's in a small hole, and when I move the rock, it moves down into it, so I can't get a view of the entire body. It's also incredibly tiny, as you can tell from the zoo in the photos. Any ideas of what it is? The lights in my tank are now on, and it closed up again.
Any ideas on what I might do to help it along? I haven't added anything to the tank in 4 months, so I've had it for at least a little while.
Thanks.
These are the best photos I can get, unfortunately.... :notsure:

 

[yosemite sam]

--Bump--

 

[bigarn]

Sorry Yosemitie .... I really haven't got a clue as to what it is, but it's good to see you back on the forum ... it's been awhile hasn't it?

I sure can see why you first thought it was algae though.

 

[yosemite sam]

Yeah, I've been in Peru for the last few months, so I'm just getting back into the swing of things. Had a bit of tank maintainance waiting for me when I got home.....

 

[speg]

It looks like a filter feeding cucumber.
When its out like that do you notice one of those 'tentacles' retracting into the hole? Like one at a time and then it comes back out into the open again?
I have several of these in my tank... and they need nothing special. Just keep doing what you're doing and they'll be happy
Let us know if it does what I described!