Worm with long legs and red square pattern. What is it?

TehBrainz · Aug 16, 2021

So my wife had me clean and move a bookshelf on the side of the tank today and I've been enjoying a view of the tank I haven't had and noticed the sand bed was pushed up on the glass.

Low and behold I see worms in the sand I don't recognize. I'm terrified for the worst ID possible, but I can't find anything that looks like these on the Googles.

Thanks in advance. Let me know if I need to nuke the whole house!

B

Timfish · Aug 16, 2021

Really cool! But how did you get Ceti ALpha VI sand eels past Star Fleet quarantine?!?!?!?!

My guess would be one of the Eunice species (aka Bobbit or Krakon worms) How big are they? How long have you had your tank running? Depending on species they'll stay small or might get HUGOMUNGUSBIG. Small ones I'd leave especially if your tank has been running a long time but keep an eye on them. (It also looks like inspite of their reputation there's plenty of 'pods crawling around so yours don't seem to be that much of a nuisance.) The HUGOMUNGUSBIG ones can catch and eat fish and inflict nasty bites.

TehBrainz · Aug 16, 2021

Timfish said:
Really cool! But how did you get Ceti ALpha VI sand eels past Star Fleet quarantine?!?!?!?!

My guess would be one of the Eunice species (aka Bobbit or Krakon worms) How big are they? How long have you had your tank running? Depending on species they'll stay small or might get HUGOMUNGUSBIG. Small ones I'd leave especially if your tank has been running a long time but keep an eye on them. (It also looks like inspite of their reputation there's plenty of 'pods crawling around so yours don't seem to be that much of a nuisance.) The HUGOMUNGUSBIG ones can catch and eat fish and inflict nasty bites.

Tanks been running for just over 3ish years, but first I've seen these guys. I've d typical bristle worms and Dorvilleidae worms in the past. I was worried it would be a type of Eunice. I saw easily 5 or so on that side of the tank. Theyre probably 2" long and 1/16 or so diameter.

Gearing up for a tank upgrade. Any way to not transfer these guys besides not transfering any rockover? I've got some rocks with encrusted frags I was planning on moving

Oh boy oh boy

Timfish · Aug 17, 2021

3 years and that's as big as they are? Honestly if it was my tank I'd be thrilled to have them. Not every Eunice genus species get's big. The smallest species only gets about 1/2" long. There's likely a lot of tanks with the smaller species that go unoticed, kinda like yours.

anthonygf · Aug 17, 2021

Timfish said:
Really cool! But how did you get Ceti ALpha VI sand eels past Star Fleet quarantine?!?!?!?!

My guess would be one of the Eunice species (aka Bobbit or Krakon worms) How big are they? How long have you had your tank running? Depending on species they'll stay small or might get HUGOMUNGUSBIG. Small ones I'd leave especially if your tank has been running a long time but keep an eye on them. (It also looks like inspite of their reputation there's plenty of 'pods crawling around so yours don't seem to be that much of a nuisance.) The HUGOMUNGUSBIG ones can catch and eat fish and inflict nasty bites.

Interesting video, thanks.

Gtinnel · Aug 17, 2021

Never seen a worm that looks like that. I agree that it is probably harmless, but if I'm not sure of that I'd remove it/them. I believe in the when in doubt take it out saying.

TehBrainz · Aug 17, 2021

Timfish said:
3 years and that's as big as they are? Honestly if it was my tank I'd be thrilled to have them. Not every Eunice genus species get's big. The smallest species only gets about 1/2" long. There's likely a lot of tanks with the smaller species that go unoticed, kinda like yours.

Always possible they came in on some frags I got a few months ago (dipped but no quarantine), but I think that's unlikely. Anything that's not one of the common and obvious RS worms brings on fear lol. I love having good biodiversity as long as it's safe of course

Gtinnel said:
Never seen a worm that looks like that. I agree that it is probably harmless, but if I'm not sure of that I'd remove it/them. I believe in the when in doubt take it out saying.

Yea I hadn't either! I've checked hundreds of pictures it feels like of "harmful" worms and can't find anything that looks like these. I will try to catch one and get it under my microscope, but can't make any promises lol

Goaway · Aug 17, 2021

This is a syllidae worm. Toss them out, they eat corals.

Worm Hitch Hikers

The identification of Worms found within live rock and live sand

chucksaddiction.thefishestate.net

look for The Syllidae

TehBrainz · Aug 17, 2021

Mibu said:
This is a syllidae worm. Toss them out, they eat corals.

Worm Hitch Hikers

The identification of Worms found within live rock and live sand

chucksaddiction.thefishestate.net

look for The Syllidae

Based on the article you linked and some various research papers I found, I don't see any claim of eating corals. Mostly omnivorous on algae or carnivorous towards bryozoa, ascidians, etc.

I dont doubt they could munch on corals. But they are nowhere near any of mine (that I can easily tell). I will try a bristle trap later and see if I can determine what attracts them. Thabk you for identifying though! That was a huge hurdle for me to overcome.

This was a paper from a specific Japanese syllidae I found. Interesting read and the paper is free!

Life Cycle of the Japanese Green Syllid, Megasyllis nipponica (Annelida: Syllidae): Field Collection and Establishment of Rearing System

Some polychaete species in the family Syllidae exhibit distinctive life cycles, in which a posterior part of the body of an individual detaches as a reproductive individual called a “stolon”. This type of reproductive mode is known as stolonization or schizogamy. Although a number of...

bioone.org

Goaway · Aug 17, 2021

TehBrainz said:
Based on the article you linked and some various research papers I found, I don't see any claim of eating corals. Mostly omnivorous on algae or carnivorous towards bryozoa, ascidians, etc.

I dont doubt they could munch on corals. But they are nowhere near any of mine (that I can easily tell). I will try a bristle trap later and see if I can determine what attracts them. Thabk you for identifying though! That was a huge hurdle for me to overcome.

This was a paper from a specific Japanese syllidae I found. Interesting read and the paper is free!

Life Cycle of the Japanese Green Syllid, Megasyllis nipponica (Annelida: Syllidae): Field Collection and Establishment of Rearing System

Some polychaete species in the family Syllidae exhibit distinctive life cycles, in which a posterior part of the body of an individual detaches as a reproductive individual called a “stolon”. This type of reproductive mode is known as stolonization or schizogamy. Although a number of...

bioone.org

They supposedly latch onto to sponges and drain them. Now, if you feel it is safe to keep, go for it.

Edit: these are not a common worm. So, you do have a unique specimen.

TehBrainz · Aug 17, 2021

Mibu said:
They supposedly latch onto to sponges and drain them. Now, if you feel it is safe to keep, go for it.

Edit: these are not a common worm. So, you do have a unique specimen.

Yea I definitely don't feel safe, but I think a successful tank occurs when we question and observe everything. Even RS fish can vary from one to another lol.

I honestly don't even know how I'd go about eradicating/removing them at this point as they are so small and in the sand. My only savior is that I'm in the midst of an upgrade with new sand and new (mostly) rock. I was planning on transferring a few center piece rocks that have coral glued and encrusted so I may need to look into special treatments for those rocks

Can't help but be somewhat excited (and scared) that these are more unique to the hobby. Makes me wonder where they came from lol

Goaway · Aug 17, 2021

TehBrainz said:
Yea I definitely don't feel safe, but I think a successful tank occurs when we question and observe everything. Even RS fish can vary from one to another lol.

I honestly don't even know how I'd go about eradicating/removing them at this point as they are so small and in the sand. My only savior is that I'm in the midst of an upgrade with new sand and new (mostly) rock. I was planning on transferring a few center piece rocks that have coral glued and encrusted so I may need to look into special treatments for those rocks

Can't help but be somewhat excited (and scared) that these are more unique to the hobby. Makes me wonder where they came from lol

I kept a eunicid worm for a year and never knew it was in my rocks. I thought all of them were gone after I tore my sand bed apart.
The fact you have something rare, maybe set up a system for it? Try to get more information if you like. I guess they like to eat dead fish and spinach. The report says they eat algae on rocks. So, this could be a very beneficial creature.

Timfish · Aug 17, 2021

To update my previous post:

3 years and that's as big as they are? Honestly if it was my tank I'd be thrilled to have them. Not every Syllid worm genus species get's very big. The smallest species only gets about a fraction of an inch, biggest a little over 5". There's likely a lot of tanks with the smaller species that go unoticed, kinda like yours and from what I've read they might be useful scavengers. It could be a very rare species you might consider getting in touch with researchers to see if they are intrerested in it.

TehBrainz · Aug 17, 2021

Timfish said:
To update my previous post:

3 years and that's as big as they are? Honestly if it was my tank I'd be thrilled to have them. Not every Syllid worm genus species get's very big. The smallest species only gets about a fraction of an inch, biggest a little over 5". There's likely a lot of tanks with the smaller species that go unoticed, kinda like yours and from what I've read they might be useful scavengers. It could be a very rare species you might consider getting in touch with researchers to see if they are intrerested in it.

Thats a good idea! I live on the coast too so I'm sure there are some nearby that may be interested. I spent the better part of the afternoon scouring the web and still couldn't find any with markings like what I saw. I'm sure there are very specific details needed for proper identification, but still its been a fun search.

I fed heavy tonight and pipette frozen mysis and krill around the sand bed in their location. They came up like nessarius snails do out of the sand and were grazing on the food. I'll try and get a video at feeding tomorrow night.

TehBrainz · Aug 17, 2021

@vetteguy53081 what do you think? You're pretty good at ID'S! Do you think this is a Syllidae worm as well? Ever seen one like this? I counted about 10 individual worms along the glass tonight.

Reattached for ease in viewing.

vetteguy53081 · Aug 17, 2021

Its either a Acoetidae or more likely phyllodocidae worm. Rare to see them and they often hide under rocks.

TehBrainz · Aug 20, 2021

Mibu said:
I kept a eunicid worm for a year and never knew it was in my rocks. I thought all of them were gone after I tore my sand bed apart.
The fact you have something rare, maybe set up a system for it? Try to get more information if you like. I guess they like to eat dead fish and spinach. The report says they eat algae on rocks. So, this could be a very beneficial creature.

Timfish said:
To update my previous post:

3 years and that's as big as they are? Honestly if it was my tank I'd be thrilled to have them. Not every Syllid worm genus species get's very big. The smallest species only gets about a fraction of an inch, biggest a little over 5". There's likely a lot of tanks with the smaller species that go unoticed, kinda like yours and from what I've read they might be useful scavengers. It could be a very rare species you might consider getting in touch with researchers to see if they are intrerested in it.