Caught this tonight. Should I be scared? Because this only half of it.

[twoahh]

http://img.tapatalk.com/d/13/11/26/me5esese.jpg

[dread240]

euchnid?

[devimik]

Looks like a normal Bristleworm to me. Eunicid worms have 5 antennae coming off their head, so unless you see that, this is probably a common Bristleworm and is beneficial to your tank. I've got tons of them in my 90g and they don't bother anything. They actually eat detritus.

[thegrun]

+1, a keeper

[marcaharding]

+2 keeper, I would have some but I killed mine during the cycle process

[leveldrummer]

I only get freaked out when i see the REALLY big bristle worms, depending on the size of this one, it doesnt seem like anything to be worried about. Im sure your tank has WAY more in it still

[Dapg8gt]

Keeper..

[Mark9]

It may be too late for a "keeper", he said he pulled 1/2 of it out of the tank.
Do they survive being cut in half?

[twoahh]

Yes they do but I've been told that once to big they can go after coral also.

[devimik]

Normal bristleworms don't go after corals as they don't have any teeth or chewing ability. They will eat dying matter, so they can suck it up. Now, true fireworms and other types of polychaetes like Eunicid worms and Hermodice worms can eat corals and small fish.