Cute worm or pest?

[JHSteepat]

I got some tb saltwater rock and sand and WOW, what a party! The rock and sand are in a separate tank for observation.

Two things:

1. I was observing the rock with a red headlamp and I saw a small shell magically rising to the side of a rock. It fell off a while later and this gray worm with at least one antenna/tentacle extended down 2” or so to the sand, picked up the shell, and pulled it into place over its hole.

It is fascinating behavior, but should I be concerned? How do I video, photo, or catch the thing to show the forum (if needed).

2. I have a couple 1-2mm pods zipping about at night. I assume they are isopods. They are fast, so how do I tell if they are cirolean, or harmless.

No pics - neither like white light.

 

[MnFish1]

I got some tb saltwater rock and sand and WOW, what a party! The rock and sand are in a separate tank for observation.

Two things:

1. I was observing the rock with a red headlamp and I saw a small shell magically rising to the side of a rock. It fell off a while later and this gray worm with at least one antenna/tentacle extended down 2” or so to the sand, picked up the shell, and pulled it into place over its hole.

It is fascinating behavior, but should I be concerned? How do I video, photo, or catch the thing to show the forum (if needed).

2. I have a couple 1-2mm pods zipping about at night. I assume they are isopods. They are fast, so how do I tell if they are cirolean, or harmless.

No pics - neither like white light.

You can post to YouTube - and then post the link (which I would like to see for 1)
I would hesitate to guess whether they are isopods vs another type without a picture

Good luck with your new rock - many of the things you got - may die off on their own.

 

[wtdenk]

Sorry for the crude screenshot, but this likely your culprit. I'm in the same situation as you just a year further down the road. I'll bet you have more than just one of these worms too. Good news is they seem pretty low on the predator worm toughness scale. I've witnessed them go after snails if given the opportunity. They use shells to glue on to their burrows to extend the length of their space which I assume allows them to grow and gives them another spot to ambush weak snails. I routinely knock down their new constructions. Not sure it matters much, but makes me feel better.

Best answer I have is it's some sort of eunice worm. Google pictures look the closest. I've also been told a dorvilleidae worm.

Bad news is that you won't be able to catch it and remove it/them (I would very much appreciate being proven wrong here). Only thing to do would be to dip the rocks, but I wasn't willing to do that. Too much life on these rocks. Didnt want to disrupt. Still seeing new stuff pop out a year in. That's what we paid for.

 

[kjkszpj9]

Sorry for the crude screenshot, but this likely your culprit. I'm in the same situation as you just a year further down the road. I'll bet you have more than just one of these worms too. Good news is they seem pretty low on the predator worm toughness scale. I've witnessed them go after snails if given the opportunity. They use shells to glue on to their burrows to extend the length of their space which I assume allows them to grow and gives them another spot to ambush weak snails. I routinely knock down their new constructions. Not sure it matters much, but makes me feel better.

Best answer I have is it's some sort of eunice worm. Google pictures look the closest. I've also been told a dorvilleidae worm.

Bad news is that you won't be able to catch it and remove it/them (I would very much appreciate being proven wrong here). Only thing to do would be to dip the rocks, but I wasn't willing to do that. Too much life on these rocks. Didnt want to disrupt. Still seeing new stuff pop out a year in. That's what we paid for.

If ur able to get a pic of its head check if it has a white ring or just a different color on one of its segments near its head, if it has a ring its an eunice worm if not then its probably a regular bristleworm, also the head has 5 tentacles compared to bristleworm that barely has any tentacles on the head or any if im sure.

 

[JHSteepat]

Thanks for the replies. This thing has tentacles and did not really look like a bristleworm at all. No bristles, just worm with definite tentacle. Sounds like a member of the Eunice family.

I heard a pop last nite so I’ll be doing some trapping, not that this thing will turn up in a trap.

I will just wait and see what survives the observation period.

 

[JHSteepat]

Here is a second worm in a different rock trying to get to a starfish in a shell. Best I can do with iphone, but ring and tentacles are there. So much for putting these in the dt. Guess I’ll break these up to remove the worms and use as rubble in sump.

 

[kjkszpj9]

white ring around its head yeah thats definitely a Eunice worm and one of the ones that probably is a predator/scavanger considering you said it was trying to get a starfish.

If you get a photo of it in regular color like a picture and if its brown/lightbrown in color then its probably the same one i had in one of my rocks and im pretty sure they dont get bigger than 20cm but mine was eating Chitons.

it might even be this one https://inverts.wallawalla.edu/Annelida/Eunicidae/Eunice_valens.html

 

[Borat]

Nice pet!