Please Help IDing (Live Rock)

[gsbrawley65]

Noticed this in my live rock. Haven’t spotted it out of the rock yet but it is moving almost continuously and curling into itself.

 

[mycholula]

So cool! (No idea what it is). Where did you get the live rock from? I got mine from TBS for my 40oz, and Im still finding stuff.

 

[saltwaterfish.com Verified Sponsor]

Looks like a bristle worm or some other kind of Polychaete. It will most likely come out in the middle of the night once the lights are off. If you throw in some sinking food around then, you should have a better chance of seeing it.

 

[keagan]

I second polychaete worm if it was my aquarium that one is big enough id try to get it with tongs on the off chance it's a gulf fireworm. Just to be able to see it better and be sure it's harmless.

 

[KrisReef]

I would pull that rock out (if you can) and put it in RODI and see if that encourages the creature to come out where we can see what it is.

Or hyper salinity, or regular salinity with Potassium chloride, just to get it where it can be clearly visible and identified.

 

[gsbrawley65]

I purchased live rock from KP Aquatics. Great stuff and full of life (unfortunately some life I may need to get rid of too).

I lost track of him for a bit but found him tonight. He was buried too deep to grab but I got a few additioinal pictures. I'm not sure this changes the advice. So, I'll hope he doesn't switch rocks and do hyper salinity this weekend.

 

[Gumbies R Us]

@ISpeakForTheSeas

 

[v3v3]

Eunice worm

 

[BryanM]

Looks like a classic bristleworm to me. Generally a good guy. Bare handed you would feel it is a bad guy, you'll end up with its bristles in your hand and be quite uncomfortable.

My tank seems to breed them, I bet if I watch at night I'd probably see 30+.

 

[EnterName]

@ISpeakForTheSeas

In every ID-thread I see you tagging ISpeakForTheSeas. That poor man has a second job thanks to you
Leave some of his insane identification skills for the rest of us please!

 

[keagan]

Ya that sure looks like a Eunice worm I'd pull that ASAP

 

[gsbrawley65]

His head looked to have multiple attenas. That was the best picture I could get as he retreated when I flashed the light. I'm going to pull the rock as soon as I'm able to confirm he's still in and then figure out the best way to get him out. Will likely be this weekend though. No current tank inhabitants. So, I just risk losing track of him (though I think he's 12+inches).

 

[gsbrawley65]

Removed. Definitely a Eunice worm. I did not get a picture as it took quite the effort. I assume I should not add the live rock directly back into my tank after two RODO dunks (and 2 hyper salinity)? I currently have it in a 5 gallon bucket to monitor as I assume there will be die off.

 

[EnterName]

Eunice worms are broadcast spawners so at least you shouldn't have to worry about eggs that might not be affected by any dips.

I would consider the rock as "dead" after a RO/DI dip. The osmotic pressure difference will kill pretty much everything on the rock.

If you want to get rid of organics you can give it a bleach bath. This will reduce the bioload the rock will cause when being put back into the tank. You can even get rid of bound phosphate by giving it a very dilute muriatic acid bath. (DO NOT mix bleach and acid those treatments have to be performed after one another with a decent RO/DI rinse in between)

For an established tank a single rock's bioload will not cause problems and you could directly add it back untreated. For a new tank the bleach treatment might help to avoid an ammonia spike, it can cause the rock to look a bit different until new coralline algae has overgrown it again.

I hope this helps