tentacles in rock crevase

[Kazarko]

I see numerous tentacles coming out of a new piece of rock I got, each less than an inch long. These clusters are occuring at like 10 spots on the rock. They have tiny little bumps on them along the tentacles and the tentacles are solid black striped with white.
Pest or not? Trying to get a pic but difficult because of the size and location of the creatures. Attached are the only good pics I have. I'm looking for info on what these are and how big they get.

 

[dcantucson]

Mini Brittle Stars. Good thing.

 

[yote]

+1 David

Their just small brittle stars.they are great additions to your CUC.

 

[Kazarko]

Thanks! Probably won't have the space for 10 full grown ones, but we'll see if they live that long. I definitely did not acclimate the rock for sensitive inverts.

 

[parrotchute]

Thanks! Probably won't have the space for 10 full grown ones, but we'll see if they live that long. I definitely did not acclimate the rock for sensitive inverts.

They won't grow bigger than they are now..appears they are a separate species that stays small.

 

[Bifferwine]

Yep, those guys stay small. They are really common hitch hikers.

 

[mng777777]

they should do just fine... good find! Congrats.