What kind of worm is this? Good or bad?

[Crystal08]

Found this coming out of my rock tonight. Please help me identify what it is and if i need to remove it. Thanks I’m advance!

 

[1epauletteshark]

Found this coming out of my rock tonight. Please help me identify what it is and if i need to remove it. Thanks I’m advance!

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That doesn’t look like you average bristle worm, I am leaning on something like a bobbit/eunicid worm but the long legs are throwing me off.
Either way, doesn’t look like a friendly guy.

 

[ISpeakForTheSeas]

That doesn’t look like you average bristle worm, I am leaning on something like a bobbit/eunicid worm but the long legs are throwing me off.
Either way, doesn’t look like a friendly guy.

Eunicid worms have tentacles on their face (typically five tentacles), so they’re usually pretty easy go identify (and, while a few Eunicids are predatory like the bobbit and Oenone fulgida, most are actually harmless/beneficial). Personally, I’d guess it’s a Syllid worm:

Based primarily on the long, hair-like chaetae (bristles) sticking off the sides, I’d guess a Syllid worm (taxonomic family Syllidae) of some kind. If it is a Syllid worm, then there’s a good chance it’s safe (and good CUC). However, some Syllids are known to eat sponges, tunicates, and - reportedly from some hobbyists - soft corals. The eating of soft corals is firmly disputed though, as many people (primarily from several years back, when Syllid worms were apparently more common hitchhikers) also report having them without issues even if the worms crawl over their soft corals regularly.

So, it’s probably safe/beneficial, but you can always sump it to be cautious, you could isolate it and offer it a cheap soft coral or two in addition to some fish food to see if it’s coral safe.

Some context for their diet (the paper linked below is “The diversity in diets of Syllidae (Annelida: Polychaeta)” by the università di lecce (the University of Salento).

https://www.vliz.be/imisdocs/publications/289130.pdf

Just for clarification here, bristle worm (while generally used in the hobby to mean a harmless polychaete worm) is actually a generic term for all polychaete worms (the bristles of the worm being called chaetae; polychaete basically = multiple chaetae). Oenone fulgida is a eunicid polychaete. The infamous bobbit worm is also a eunicid polychaete. However, not all eunicid polychaetes are predatory/bad.

If you’re worried about a “bristleworm” in your tank, then I’d try baiting it with snails and/or clams or similar and seeing if it is super fast to strike (like the predatory bobbit worm and company) or if they’re more laid back in approaching the potential prey. If it strikes quickly or takes live prey, you should probably remove it from your tank.

 

[TnFishwater98]

Yank it if you can…

 

[TnFishwater98]

Worm Hitch Hikers

The identification of Worms found within live rock and live sand

chucksaddiction.thefishestate.net

 

[1epauletteshark]

Eunicid worms have tentacles on their face (typically five tentacles), so they’re usually pretty easy go identify (and, while a few Eunicids are predatory like the bobbit and Oenone fulgida, most are actually harmless/beneficial). Personally, I’d guess it’s a Syllid worm:

That looks more like it, a photo of it’s face would help with a certain ID

 

[Crystal08]

Eunicid worms have tentacles on their face (typically five tentacles), so they’re usually pretty easy go identify (and, while a few Eunicids are predatory like the bobbit and Oenone fulgida, most are actually harmless/beneficial). Personally, I’d guess it’s a Syllid worm:

I got it out to be on the safe side. Still not sure exactly what it is after looking it up though.

That looks more like it, a photo of it’s face would help with a certain ID

I removed it in case I couldn’t find it again later

Yank it if you can…

I was able to

 

[TnFishwater98]

I got it out to be on the safe side. Still not sure exactly what it is after looking it up though.

I removed it in case I couldn’t find it again later

I was able to

That’s a long worm!

 

[Tired]

Oo, neat! Poor thing's all confused, though- best to put it out of its misery if you don't plan to 'fuge it.

 

[Crystal08]

That’s a long worm!

It was really long and gross. Glad it’s out of the tank

 

[Crystal08]

Oo, neat! Poor thing's all confused, though- best to put it out of its misery if you don't plan to 'fuge it.

We did. I felt bad but I didn’t know what else to do but make it quick for the poor guy

 

[Tired]

Probably cleaner than it would have gotten in the wild, since something would have inevitably eaten it. Clove oil is good to keep on hand both for livestock euthanasia and to humanely dispose of pests, for future reference. Kudos for being concerned for its suffering, though; even worms deserve that bit of respect.

That is promising for whatever rock it crawled out of. If something that big was in there, imagine what else is hanging out! Should be all sorts of cool things, most of them probably harmless-to-beneficial.

 

[Goaway]

That was a syllidae worm. There's no real evidence of them being dangerous. Maybe one of the most missunderstood hitch hiker we get.

 

[TnFishwater98]

That was a syllidae worm. There's no real evidence of them being dangerous. Maybe one of the most missunderstood hitch hiker we get.

I try to keep a Length Limit on any worm.. Luckily I’ve never had a huge one to pull out. My first tank I had a common Fireworm that were round and almost looked like red earth worms. They would get pretty long and fat. Luckily, I don’t have those anymore.

 

[Goaway]

I try to keep a Length Limit on any worm.. Luckily I’ve never had a huge one to pull out. My first tank I had a common Fireworm that were round and almost looked like red earth worms. They would get pretty long and fat. Luckily, I don’t have those anymore.

One day, I will remember this post and snag a pic of my fireworms. They make quick work of anyone dying.

I do want to get some syllidae. They have absolutely some amazing movements. The only one I ever found I researched and was told it was to go. I regret it today. I did have a very large eunicid worm. Over 2' in length. They are a battle to remove.

 

[TnFishwater98]

Just read syllidae worm’s feed on hydroids…

 

[TnFishwater98]

One day, I will remember this post and snag a pic of my fireworms. They make quick work of anyone dying.

I do want to get some syllidae. They have absolutely some amazing movements. The only one I ever found I researched and was told it was to go. I regret it today. I did have a very large eunicid worm. Over 2' in length. They are a battle to remove.

If they tear does it become 2…?

 

[TnFishwater98]

 

[Goaway]

If they tear does it become 2…?

From what I've read, the eunicid will break off the tail and grow a new head. We used to think they didnt have a brain. Now they think the have more than one. I can't keep track.

The syllidae I found was rather sensitive. Not a good pest trait.

 

[Crystal08]

That was a syllidae worm. There's no real evidence of them being dangerous. Maybe one of the most missunderstood hitch hiker we get.

My biggest worry was my soft corals