What is this?- Purple spider looking thing

[Socaldayz]

I found this inside/under my Leptoseris. There is actually a few things under there. I found a bristleworm, this weird purple thing, and a polyp thing the LFS told me to pluck off when I should a picture.

I had the coral on a plug and was taking it off to finally glue down when I found these things.
Thank you in advance.

 

[Tired]

Brittle star. Useful detritivore. Probably best to put it back in case it's still alive.

 

[vetteguy53081]

I found this inside/under my Leptoseris. There is actually a few things under there. I found a bristleworm, this weird purple thing, and a polyp thing the LFS told me to pluck off when I should a picture.

I had the coral on a plug and was taking it off to finally glue down when I found these things.
Thank you in advance.

reef safe micro brittle star

 

[Socaldayz]

Ok, cool. Thank you. I only had it out of the water for less than 2 minutes, then put it in a cup with tank water until I could figure out what it was.

 

[Tired]

Kudos, that's definitely the way to go with unknown creatures. Though, for future reference, it's generally easier to ID aquatic critters when they're in the water. A lot of them have parts that will shrink down or otherwise not look the same on land.

You probably have more of these. If you see weird little striped, hairy tentacle things sticking out from inside your live rock, that's the legs of the brittle stars reaching out to try to catch food. They're harmless to anything that isn't detritus, as they stay tiny.