Centipede Hitchhiker?

[Joshjr619]

I was just looking at my tank and saw a 3-4 inch long centipede looking creature hiding in my live rock. I have had my tank for about a year now and this is the first time seeing it. Couldn't get a picture as it's hiding within the rock. Looks just like a centipede, is this good or bad? Need help guys!!

 

[Chad]

Could be a dragonfly nymph but without a photo it's all just guesses at this point. If that's what it is, then it needs to be removed.

 

[Joshjr619]

Doesn't look like that one trying to get a picture but really hard. Looks like a centipede as it has a lot of legs and looks like it's actually longer, maybe 6 inches.
Looked at some pictures looks like a Eunice worm. Scary....
Looked at some pictures looks like a Eunice worm. Scary....

 

[Chad]

Oh...I had my brain on FW and didn't even look at the forum this was under...marine...duh...
 
There are a few worms that come to mind. The most common is the bristle worm, though it doesn't have lots of legs it can look like it does. 
 
The other is a syllidae worm, also known as a detritus worm. 
 
And the last is, as you mention, the Eunice or Bobbit. 
 
My guess is the first just based on commonality but the others are not unheard of for sure. 
 
If you can manage to trap it and post a photo we will be able to tell. 
 
If it's the first worm then it's likely a type you can leave in the tank and that will be beneficial in scavenging. If it's one of the latter two then it will need to go. 

 

[Donya]

I will also toss out Oenone fulgida and its relatives (Oenonidae) as another group that are sometimes described as centipede-like and also need to be removed.

 

[Joshjr619]

I haven't got a picture yet but it looks something really, really close to this.
I haven't seen its whole body yet but I'm guessing it could be around 4-5 inches long. It won't completely come out it just sticks an inch or so out of the live rock then goes right back in.

 

[CrimsonBoli]

 
And the last is, as you mention, the Eunice or Bobbit. 
 

 
That looks horrific! 

 

[Chad]

That's a good sized bristle worm in the picture above. They make good scavengers.

 

[Donya]

It is probably safe, particularly given the described, timid behavior. However, it's worth noting that while the vast majority of time the hitchhiker bristleworms are good guys, but every now and then a bad, predatory species shows up such as Herodice carunculata (identifiable by a knobbly bit on the nose called a caruncle). 

 

[Chad]

Yes, we call those fire worms (generic term). While beautiful they are nasty.

 

[Joshjr619]

This is my best picture so far he came out for a little bit this morning.

 

[Joshjr619]

Had a snail die, crabs were feasting and mr. Worm came out to take a bite. Should I get rid of him? And how should I go about removing him? I went too grab some stuff and not even 2 minutes later he was gone. Going to be really hard to catch this little booger. If I could leave him I would but I intend to get anemones and corals down the line as I'm loving this saltwater adventure more and more.

 

[Chad]

Probably not. Taking a bite of detritus, leftover food, and dead things is what worms do the best. For the one you see there are likely many more you don't. Check our tank out at night after the lights have been off for a few hours and the room nice and dark. You'll see lots of things moving about you didn't know where there. Some are good, most are good, and a few aren't. 

 

[Joshjr619]

Thanks for everything tcamos and donya your info really helped me out. I'll just let mr. Worm be, I'm sure there's probably many more creatures lurking at night. Thx again!!