2-inch inch ribbon-like creature

accidental_reefer · Dec 16, 2023

Hi all, I spotted something cloudy white, longish, and flat in the process of going into/retracting inside a tiny hole in a piece of Marco rock sitting on top of TBS live rock. Originally thought it was perhaps solidified glue from trying to reglue a frag. But then I saw it retract and elongate randomly. For the past few hours, it’s been stretching around the rock at different angles from the same starting position, so I can’t confirm how long it really is. Going through the forum threads, i though it was a ghost or Acoel flatworm but I haven’t seen any pics of the worm extending as long as this one.

Help IDing appreciated. As well as whether I should grab a tube and suck the thing out of the tank.

Bonus ID, this morning I saw a worm swimming/swiggigling in the morning until I turned on the lights — at which point it went limp and floated down onto an egg crate holding my frags. Is this a harmless bristle worm?

littlefoxx · Dec 16, 2023

@ISpeakForTheSeas

Reefkeepers Archive · Dec 16, 2023

Inital thought is spaghetti worm though their feeding arms are not flat. I have no idea as well. @ISpeakForTheSeas?

ISpeakForTheSeas · Dec 16, 2023

accidental_reefer said:
i though it was a ghost or Acoel flatworm but I haven’t seen any pics of the worm extending as long as this one.

Help IDing appreciated. As well as whether I should grab a tube and suck the thing out of the tank.

At that size and shape, I'd guess it's a Cestoplana sp. - a kind of flatworm. Unfortunately, all I can tell you about Cestoplana spp. is that they have uniquely good regenerative abilities compared to most of their relatives. So, I don't know if it's harmful or not, but - based on its relatives - I'd assume you don't want to keep it.

That said, it could potentially be a Prosthiostomid (taxonomic family Prosthiostomidae) flatworm (which are usually shorter than Cestoplana spp.), or possibly a Nemertean/Ribbon Worm (taxonomic phylum Nemertea).

accidental_reefer said:
Is this a harmless bristle worm?

I can't say for sure on this one without a closer up, clear pic under white light, but probably - all I can tell for sure from the pics is that it's a polychaete of some kind.

DaJMasta · Dec 16, 2023

The last two pics are definitely a bristle worm.

Reefkeepers Archive · Dec 16, 2023

@EeyoreIsMySpiritAnimal why the "Haha" reaction? Was talking about the first one.

accidental_reefer · Dec 16, 2023

coming across “euphlyllia eating flatworm” when it was stretching a half inch away from my hammer induced me in a bout of panic to shove my arm in the tank and pull out the rock asap knocking over a bunch of frags. My corals are ticked off from chaos the last two days.

Perhaps just a coincidence, noticed a dead astrea right around the rock. Could’ve been my hermits but they’ve been really well fed the last past week from snacking off the gorilla crab trap and no crab took over the shell as in the past. Should I toss out the shell in case a worm is hiding in there? A bumble bee snail is sitting in the opening right now so haven’t been able to shake and test.

If I boil the rock in hot water, will that be enough to nuke whatever is in/on it? Or should I just chuck the rock? The rock was just being used to hold up a rack so don’t care either way.

Thanks for the helpful education.

ISpeakForTheSeas · Dec 16, 2023

accidental_reefer said:
Should I toss out the shell in case a worm is hiding in there? A bumble bee snail is sitting in the opening right now so haven’t been able to shake and test.

You can pull the shell out and inspect it if you want, but I doubt a worm is hiding in it.

accidental_reefer said:
If I boil the rock in hot water, will that be enough to nuke whatever is in/on it?

Please don't boil any rocks or other things you pull out of your tank - you don't want to aerosolize something dangerous (like palytoxin).

If you want to get rid of whatever is in/on the rock, then you can do things like bleach the rock, soak in hypersaline water, etc.

Cichlid Dad · Dec 16, 2023

accidental_reefer · Dec 16, 2023

ISpeakForTheSeas said:
You can pull the shell out and inspect it if you want, but I doubt a worm is hiding in it.

Please don't boil any rocks or other things you pull out of your tank - you don't want to aerosolize something dangerous (like palytoxin).

If you want to get rid of whatever is in/on the rock, then you can do things like bleach the rock, soak in hypersaline water, etc.

phew. Thanks for the health advisory.

accidental_reefer · Dec 16, 2023

Cichlid Dad said:

Gross. Okay, taking no chances; chucking the rock.

Reefkeepers Archive · Dec 16, 2023

Cichlid Dad said:

I was thinking the same thing as said above, however...

This is from my tank, there's just something off about what OP has...

Cichlid Dad · Dec 16, 2023

accidental_reefer said:
Gross. Okay, taking no chances; chucking the rock.

My post shows what a spaghetti worm looks like. Spaghetti worms are good

Reefkeepers Archive · Dec 16, 2023

Cichlid Dad said:
My post shows what a spaghetti worm looks like. Spaghetti worms are good

Still a bit skeptical about it being spaghetti worms.. @accidental_reefer is there more than one clear white arm extending or do you only see one? If you follow it to the base is it coming out of a tube made of sand?

Reefering1 · Dec 16, 2023

Reefkeepers Archive said:
Still a bit skeptical about it being spaghetti worms.. @accidental_reefer is there more than one clear white arm extending or do you only see one? If you follow it to the base is it coming out of a tube made of sand?

Its not a spaghetti worm. That's what he is saying