Hitchhiking Brittle Stars?

[r1ckep]

I noticed a fuzzy, red and white banded thing slithering out of a rock this week and thought I had finally joined the club of having to deal with bristle worms. But, when I tried to remove it, I found that the “worm” was actually attached to a central point with more arms sticking out. Not only that, it tenaciously moved away and rapidly withdrew into the rock. Last night, I saw TWO sets of these things when looking around the rockwork with a flashlight. I’m thinking that I may have (at least) two red/white striped brittle stars. I can only guess they showed up as hitchhikers. Research online leads me to believe they are good and won’t harm my fish or softies. Can anyone confirm my suspicions and give me an idea how big they may get? I’ll try to add a pic if I can capture one in the open, but they seem to love the rocks and only come out (a little) at night. Thanks!

 

[JumboShrimp]

I'd say 'keepers' unless they somehow prove destructive down the line. People pay good money for them at their LFS-- yours were free.