Pincushion hosting bristleworm?

[helwrj28]

I've had a pincushion for about a week now and tonight I noticed this work on the surface of the urchin!

First off I'm curious for an ID, and second, if I should be concerned and remove/relocate, thanks!

 

[DJC]

I've had a pincushion for about a week now and tonight I noticed this work on the surface of the urchin!

First off I'm curious for an ID, and second, if I should be concerned and remove/relocate, thanks!

Urchins have been known to house bristle worms without a better shot of the worm it’s prolly going to be hard to ID

But there have been cases where urchins have rented out space to worms without any issue in a really weird symbiotic relationship

Unless this worm is a parasitic which cannot tell from the pic

 

[helwrj28]

Urchins have been known to house bristle worms without a better shot of the worm it’s prolly going to be hard to ID

But there have been cases where urchins have rented out space to worms without any issue in a really weird symbiotic relationship

Unless this worm is a parasitic which cannot tell from the pic

Sorry, that's the most clear pic I could get!

The worm is brownish in color, has clear segments, and seems relatively flat, and has spikes on the edges.. I don't have any experience with ID of worms and I certainly don't know what a small bristleworm looks like but based on their description that's what I'm leaning on...

As far as parasitism, I don't see the worm harming the urchin (but I'm not really sure what to look for besides just stress/dying response from the urchin), and I'm only seeing the work come out at nighttime...

As a precaution should I try to remove/relocate the worm or just leave it?

 

[DJC]

If you see no change in the urchin I would prolly leave it there bristles characteristics is that their night time creatures I read online 1 guy had a bristle in his urchin permanently they formed a symbiotic relationship and never harmed the urchin just hitchhiked along with him grabbing the food then jumping back in when done

If you see your urchin going down hill then I would suggest removal