Help: Can anyone tell me what this is??
 

See picture linked to the post. I thought this might be a Bristleworm but I have other smaller Bristleworms in my tank and this guy is HUGE...he can't be good.

Looks like a eucinid worm...which I believe can/will wreak havoc on your tank.....kill it....kill it with fire.

How do I kill it? I tried long tweezers and the moment i get them in the water he darts under the live rock.

After some quick googling and reading a couple of forums on here it appears that people will take the rock out and do a fresh water dip and or pour club soda on the rock? Do some more research, but it seems like they are really difficult to trap and catch.

Hopefully someone else can chime in with more advice. Glad it's not in my tank, give me the heebie jeebies just looking at your picture :eek1:

How big do you think it is? Your picture makes it look like it's rather round. They are sometimes the cause of mysterious fish disappearances and dying corals.

Bait an acclimatization box where the lid can be slid closed easily & wait

thats one nasty looking captive you have. Probably as bad as a polyclad imo

Here is an article on these not so lil worms in a public aquarium;
http://www.dailymail.co.uk/sciencete...oral-reef.html

Yep the nasty Bobbit worm. There was one caught that was something like 9 FEET was a sight to see. Google Bobbit Worm and you will find all kinds of stuff about them. They will eat corals too among other things in your tank.

you can try many different ways to get it out. you can try the bottle trap method, but i dont know how big the worm is and if it will fit in the bottle.

i have heard of the 'panty hose' method where you put some food in a panty hose. supposedly, the worm's bristles will get caught in the panty hose.

you can also try stunning it. go down in the middle of the night, and if you see it. shine a flashlight right at it. you can then proceed to try to get it out with some tongs.

i hope this helps, it really sucks to have that in a tank

With using tongs you'll more than likely break it in half or more pieces. I think the bottle trap might be the best bet but us a 2 liter bottle :D

i like the pvc or bottle trap method it really does seem to work wonders. speaking of wonders... im wondering why this is in the cephalopod section...

I dont think they eat corals.. more like sculpture them and use in there burrows..
I would sump him, interesting creature.

Any update?

dying corals

Hello, I had one of those destroying my corals and eating my fish once. If this worms break they have the ability to grow another head and the problem continues. They don't really ever fully leave the rock cavity so any method above can potentially cause them to split. Unfortunately and as painful as it is, I recommend you find the rock he's hiding in, remove it and dip it in fresh water. The worm will dart out but be careful that no pieces stay behind. Hope this helps.

If you see and remove one, can you assume there are others, and are they self replicating/hermaphroditic?

How can I tell the difference between a good worm or a bad one? I have tons of worms big and small in my tank. Always assumed they were bristle worms and no problem until I saw this thread.

Ah... think I just found my own answer. Just the one type of worm that's bad.