Just pulled this outta my sump…

[Andynz2000]

Just pulled this outta my sump. My tanks probably 3-4 months old…. Is this a bristle worm?? It’s so goddam big I didn’t know they could grow so big and fast.

 

[Zoa_Fanatic]

Just pulled this outta my sump. My tanks probably 3-4 months old…. Is this a bristle worm?? It’s so goddam big I didn’t know they could grow so big and fast.

Looks like a bristle worm to me.

 

[Hendrix]

They can get a lot bigger than that 18-24"

 

[Andynz2000]

Should I have left it in the sump?

 

[thatmanMIKEson]

No ! But I have them in my rock get em out no harm until you get poked by it or they get big enough for sleeping fish..jmo

 

[bnord]

it got that big by eating sumpthin' and you have the choice of leaving in there and letting it eat, or letting the detritus build
In another couple of months you will find them under rocks in the display as well I would bet
I put an arrow crab in the chaeto-bed as I understand they will eat small worms, and the crab is growing too

 

[Gtinnel]

Pic is blurry but agreed it just looks like a regular bristle. From the looks of it on the paper towel it doesn't look that big either.

 

[bnord]

and based on the conflicting messages, guess you can see the jury is out

 

[Gtinnel]

it got that big by eating sumpthin' and you have the choice of leaving in there and letting it eat, or letting the detritus build
In another couple of months you will find them under rocks in the display as well I would bet
I put an arrow crab in the chaeto-bed as I understand they will eat small worms, and the crab is growing too

 

[DedElvis]

Just pulled this outta my sump. My tanks probably 3-4 months old…. Is this a bristle worm?? It’s so goddam big I didn’t know they could grow so big and fast.

That is indeed a bristle worm. I let them get out of hand in a 29gal I had in the 90's - the real live rock I purchased came with all surprises including a mantis shrimp, aiptasia, spiny sea urchin and - bristle worms. I let them get out of hand until you could see them in the substrate against the glass. Ugh.

 

[damsels are not mean]

Regular bristle worms do not get 18-24"... I think there is a lot of confusion around the term but generally there are 3 kinds of "bristle" worms.

There are the small ones like the one you have here, which is just a detritivore and poses no harm to your tank. It eats the stuff that nobody else would, much like an earthworm. A few of the larger bristle worms like this one will have a painful sting, but not all can penetrate human skin. Mine haven't stung me in about a decade of doing this. I think these are in 99% of tanks and are nearly unavoidable. Many animals will eat them including some coral banded shrimp, wrasses, and even corals if they catch them. Sometimes clownfish will feed them to their host anemone/coral. Here is a pic that was posted by reef builders just today of an elegance eating a bristle worm.

Next up are "fireworms" which have a very different appearance. They all sting bad and are all opportunistic predators much like crabs. Some may eat corals, some will try to catch fish and inverts, but they should definitely be removed when you see them. They get much larger and fatter.

Finally are the eunicid or "bobbit" worms which are probably the worst live rock pest in existence. They are identifiable by the antennae and mouth parrs they have. This is a pic of a small one, but they can grow to several feet long if not more and will eat literally everyting. This is a "tear your tank down" kind of thing when it gets big.

 

[polyppal]

They get much bigger and nastier

 

[damsels are not mean]

They get much bigger and nastier

 

[Sean Clark]

Here is a pic that was posted by reef builders just today of an elegance eating a bristle worm.

So romantic. Just like Lady and the Tramp...

 

[Jeffcb]

They can get huge.

 

[homer1475]

They can get huge.

That 100% is a fireworm, not the common bristle worm found in every tank.

The color alone gives it away.

 

[Duncan62]

Just pulled this outta my sump. My tanks probably 3-4 months old…. Is this a bristle worm?? It’s so goddam big I didn’t know they could grow so big and fast.

That's not that big. Just wait. He'll grow and clean up your tank. When you get to many remove them. Easy to trap.