Pest ID on TBS Live Rock

[ReefTanker91]

Hello beautiful people. Was wondering if someone could help identify if the worm that comes out of the hole just a regular bristleworm or something more concerning.

I notice it does have long antenna like things from its head. Video below.



I also have these two crabs. It looks like they have banded legs. I’m not sure if they are filter feeding but, sometimes it looks like they are but other times it looks like they are scraping something of the rock and eating. Video linked below.



I did also see a long thick tube worm under my live rock a few times but it was so sensitive to the light I couldn’t get my camera out quick enough to get capture it. I’m not sure if it was just a big bristleworm or a some sort of eunic worm. It was more tubular shaped than a bristleworm would be.

Any help on identifying these things would be appreciated.

I am really excited about starting to get cuc and corals going but am now regretting going the live rock direction because of these unknown pests and if they will kill my corals or live stock.

 

[DDenny]

Really hard to see with the lighting but I also realize that they scatter with light. Have you checked the tabs page for hitchhikers?

hitchhikers – Tampa Bay Saltwater

They have a pretty good pictures of common hitchhikers.

 

[ISpeakForTheSeas]

Yeah, I can't see the worm at all at the moment - with the crab, does it have three pairs of walking legs or four?

 

[OrionN]

Crabs have 2 claws and 4 pairs of legs. Some swimming crabs have the last pair of legs modified for swimming .

 

[ISpeakForTheSeas]

Crabs have 2 claws and 4 pairs of legs. Some swimming crabs have the last pair of legs modified for swimming .

Yeah, true crabs have 4 pairs of walking legs while porcelain crabs and squat lobsters have 3 - the body shape (which is quite tough to actually see in the video) and long claws of OP's crab leave me wondering if they have one of those.

 

[JoJosReef]

For the first video, it is hard to see, but it could be a Eunice worm, which can come on gulf rocks. You will have to see if you can count the # antennae coming out the front if the head. If there are 5 of them pointing straight out in a star shaped pattern, likely a Eunice worm. They are generally considered to be undesirables, but so far I haven't seen accounts of the gulf species being harmful, and I've had a few myself, and one currently.

The crabs are also hard to see, but I suspect you have a porcelain crab there. Check to see if they have 6 legs instead of 8 (not counting the claws). Porcelains have 7th and 8th appendages, but they tuck them away and use them like windshield wipers. If 8 clear legs, thats a true crab and might be a baddie. Otherwise, if it's a porcelain, definite keeper!

 

[ReefTanker91]

Thank you everyone. I’ll try taking some better shots tonight or count the antennas and legs. Crabs look like they have 6 legs total plus the claws and windshield wipers.

Wishing you and your loved ones a safe and meaningful Memorial Day.

 

[LiverockRocks]

Thank you everyone. I’ll try taking some better shots tonight or count the antennas and legs. Crabs look like they have 6 legs total plus the claws and windshield wipers.

Wishing you and your loved ones a safe and meaningful Memorial Day.

You can also email us directly for identification.

 

[LiverockRocks]

Thank you everyone. I’ll try taking some better shots tonight or count the antennas and legs. Crabs look like they have 6 legs total plus the claws and windshield wipers.

Wishing you and your loved ones a safe and meaningful Memorial Day.

Windshield wipers = Porcelain crabs

 

[ReefTanker91]

I believe what I have is some sort of eunice worm. Was able to get a decent video of it last night. I did have him look directly at me at one time. I couldn’t see any mandibles on its mouth when it would open it. Just a perfect circle. I wasn’t able to count the antennas with the red light unfortunately.

I know it’s hard to tell me exactly what worm this is my main concern is it safe for corals, cuc or fish. It’s made its burrow in a platform piece of Marco rock that my large scaped rock sits on. If it’s a problem worm I’d try taking it out but if it’s isn’t I would just leave it in.

 

[JoJosReef]

I'd bet coral that it is a Eunice worm. For at least some of the Gulf species, you won't see the mandibles retracted like you see with bobbit worms waiting to snatch fish. This is what you will see:

Mandibles tucked up in their little kissy face. Not a cute kissy face. The only time I've seen them pull out their mandibles was when I actually nabbed one for just a second and it attacked the tongs (!!!). Startled me so much I released pressure and the Eunice worm escaped back in its hole.

The bad news is, I've found them nearly impossible to remove. I've taken out rocks and given them hot water blasts in the holes, fizzy water, worm traps, manual capture. Nope. They are lightning fast and rarely venture fully out of their holes. Even if you do nab one, you'll likely break it into at least two parts, and they regenerate heads, so you could end up with more than one.

The neutral (not exactly "good") news is that some, if not most, species we get from Gulf live rock seem to be the smaller detritivore variety, scavenging about and not hunting our fish and snails. I've watched mine "munching" on the live rocks and even getting up close and personal with my snails, but I've yet to witness a snail attack. I have mysterious snail deaths, but I don't know if it is because the of the Eunice worm(s) or something else.

I'd not worry too much about it. But maybe check in every now and then at night with that red flashlight and see what it's up to!

 

[ReefTanker91]

Thank you JoJo. I need to stop spending so much time battling these pests. I wish there was a fish that could hunt these things like ciroland isopods and unwanted worms, crabs. I was thinking a Valentin puffer or some sort of wrasse but not sure.

 

[crab burglar]

Thank you JoJo. I need to stop spending so much time battling these pests. I wish there was a fish that could hunt these things like ciroland isopods and unwanted worms, crabs. I was thinking a Valentin puffer or some sort of wrasse but not sure.

Like the above mentioned, this is most definitely a type of eunicid....why in the hell leave it to chance, in a DT? You are fortunate enough that this wasn't discovered months or years after starting the tank. There is still a chance it has not yet reproduced, and isolated to this rock.

It may be "harmless" now, but it can easily become opportunistic as it grows. If it is fast, equipped to hunt, and bite into tissue with actual jaws....it's a matter of time, size, and opportunity.
Also as mentioned, they can be difficult to remove. But not impossible. Since this is still a new tank, it hopefully wouldn't be too invasive to take that rock out and just...bash the **** out of it. Take a hammer and crack it in half, then again. And again. Until you find it's burrow and it has nowhere to go.

It's gonna suck, but I highly suggest you remove it now. I, for one, do not have the finances to bet against another one of these potentially becoming a hunter and killing the things which I spent time, money, and effort into cultivating. If you don't mind rolling the dice, my hats off to you. But I couldnt.

Why risk it?...
As for the crabs, I honestly don't know. If you can confirm they are porcelain, then fine. If not beyond a shadow of a doubt? Caution should apply here as well. Maybe get a small species tank and see how they shake out.

 

[OrionN]

I got some interesting animals from TBS. So far I only have pest anemones and a few crabs and shrimps that are predatory.
I would leave the worm alone. Hard to get them out anyway without killing a lot of animals. Innocent until proven guilty and get life in sump or death for me.

 

[mtfish]

I have at least one of these worms in my tank for 15 years. Mostly eats algae and likes to move stuff around the mouth of his burrow. No telling how big it is now, but it was about 11" when he was moved from the 75 gallon old tank to the new tank (2013). In my experience, most of these polychaetes are not fish eaters.

 

[ReefTanker91]

Thank you for your reply Crab Burglar, I would rather take my chances than smash up all of the live rock I paid good money for and scaped.

The one I have is small and there is a chance I won’t even find him even after smashing all of the rock up. I did give it a lot of thought but I like the rock and I don’t want to kill off the other life that came with it or the beneficial bacteria. It has a lot of filter feeders, snails, and even clams.

I read the thread linked below where he was dealing with a bobbit worm, it was a 4ft worm that was able to hide itself in a 1 to 2 inch part of the rock.

The Bobbit Worm Chronicles

www.michiganreefers.com

The worm I have is white in color and I believe only has 3 tentacles, I’m hoping it’s one of the smaller detritivore variety. The ones that typically cause issues are dark in color.

 

[BiggestE22]

Like the above mentioned, this is most definitely a type of eunicid....why in the hell leave it to chance, in a DT? You are fortunate enough that this wasn't discovered months or years after starting the tank. There is still a chance it has not yet reproduced, and isolated to this rock.

It may be "harmless" now, but it can easily become opportunistic as it grows. If it is fast, equipped to hunt, and bite into tissue with actual jaws....it's a matter of time, size, and opportunity.
Also as mentioned, they can be difficult to remove. But not impossible. Since this is still a new tank, it hopefully wouldn't be too invasive to take that rock out and just...bash the **** out of it. Take a hammer and crack it in half, then again. And again. Until you find it's burrow and it has nowhere to go.

It's gonna suck, but I highly suggest you remove it now. I, for one, do not have the finances to bet against another one of these potentially becoming a hunter and killing the things which I spent time, money, and effort into cultivating. If you don't mind rolling the dice, my hats off to you. But I couldnt.

Why risk it?...
As for the crabs, I honestly don't know. If you can confirm they are porcelain, then fine. If not beyond a shadow of a doubt? Caution should apply here as well. Maybe get a small species tank and see how they shake out.

Eunicid worms never stop growing if I am correct. It’s probably not a bobbit but if it’s not feeding regularly it may start with CUC attacks. Thing could get really big or at least long.

 

[ISpeakForTheSeas]

The worm I have is white in color and I believe only has 3 tentacles, I’m hoping it’s one of the smaller detritivore variety. The ones that typically cause issues are dark in color.

Eunicid worms never stop growing if I am correct. It’s probably not a bobbit but if it’s not feeding regularly it may start with CUC attacks. Thing could get really big or at least long.

Eunicids will stop growing eventually - they have max sizes they're known to attain; if the worm only has 3 tentacles, then it's not a Eunicid:

Eunicids have the five tentacles (the "five prostomial appendages" listed below), so I really doubt yours is a Eunicid worm:

"3.2. Morphology​

Eunicidae is defined by two synapomorphies, dorsal buccal lip fused to the dorsal side of the prostomium and dorsolateral fold anterior extensions medially connected [11] (Figure 5A–E). Additional diagnostic features are present at prostomium, peristomium and jaws. These are ventral buccal lips with median transverse groove, one (single median antenna) to five prostomial appendages (a pair of palps, a pair of lateral antennae and a single median antenna), double ringed peristomium (Figure 1A and Figure 5A–E), and asymmetric eulabidognath maxillae (Figure 3G). The family encompasses great length variation, bearing species from few millimeters to few meters long. All species have a variable number of chaetigers."*

Regardless, as mentioned, your worm is most likely completely harmless/beneficial (even if it is a Eunicid species):

Generally speaking, Dorvilleids are harmless/beneficial. Eunicids, on the other hand, can be either harmless/beneficial, mildly risky (think opportunistic predators eating things like snails, small crustaceans, fish larvae, etc. when starved or when the prey is weak enough), or outright predatory. Some are predators while others are literally herbivores (fun fact, even some of the predators - such as the infamous bobbit worm - will still take algae when given the chance). With that in mind, many (possibly most) Eunicids are also harmless/beneficial, so even if it's a Eunicid, it may not be a bad thing.

*Source:

The Current State of Eunicida (Annelida) Systematics and Biodiversity

In this study, we analyze the current state of knowledge on extant Eunicida systematics, morphology, feeding, life history, habitat, ecology, distribution patterns, local diversity and exploitation. Eunicida is an order of Errantia annelids characterized by the presence of ventral mandibles and...

www.mdpi.com

For anyone who's curious, the article below is a fantastic resource on Polychaetes (the supplementary material that details family by family diet, habitat, and more is especially good IMO, though it is 340 pages long - I haven't gotten through all of it yet):
https://www.annualreviews.org/doi/10.1146/annurev-marine-010814-020007