Inverts on tuxedo urchin

[tenurepro]

Just got this blue tuxedo urchin; noticed a few black blotched that stood on on its blue skin. Tried to scrap them off and they started moving!
Removed 2 of 2 (at least the one I can see)
Here is the first... most likely an arthropod, but what?

Second one is missing the head, note the feather like appendages

Any ID would be greatly appreciated!
Also, do I add the urchin to the tank?
I do have 3 wrasses but worries about taking my chances

 

[Dancingmad]

Cooool looking!! But then again i like critters. Hope its not a pest!

 

[azbigjohn]

Just got this blue tuxedo urchin; noticed a few black blotched that stood on on its blue skin. Tried to scrap them off and they started moving!
Removed 2 of 2 (at least the one I can see)
Here is the first... most likely an arthropod, but what?

Second one is missing the head, note the feather like appendages

Any ID would be greatly appreciated!
Also, do I add the urchin to the tank?
I do have 3 wrasses but worries about taking my chances

I looked through Lionfish Lair's Hitch hicker's guide (https://www.lionfishlair.com/hitchhikers-guide/) and didn't find anything that exactly matched it.

I think the wrasses are a good bet to take care of it either way. Hopefully one of the experts will chime in!

 

[tenurepro]

I am rethinking this - seem more of a segmented worm? Debating about doing a little weak dip for the sea urchin in revive

 

[Maritimer]

Looks like a polychaete worm to me as well - though beyond that level, I cannot identify it.

~Bruce

 

[tenurepro]

Eunice worm maybe? Ps I think the two parts picture in the first post are actually the head and tail of the same worm. I likely broke it in two when trying to catch it. The urchin is now in qt. I'll observe it for a while before figuring out what to do

 

[K. Steven]

That looks like the posterior end of a fireworm, potentially Hermodice

 

[tenurepro]

Thanks for the tips everyone. I think the 'bristles' in the last shot indicate some type of bristle worm; have been doing some reading and there are over 10k species so will be hard to get an exact id without further study. The urchin in question is in my quarantine tank, happily eating nori. Will give it another few days then inspect it again for hitchhikers, in case it was carrying more than one worm

 

[DeniseAndy]

Those silly urchins will carry anything on them. I know not helpful for identify, but I would agree you are looking towards the "bristle worm" area.