mystery worm ID?

[Peter Houde]

Please suggest ID of this mystery hitchhiker (worm?) that came on a plug of galaxia. It grew fast, larger, and onto the base of the coral. It seemed to badly irritate the galaxia on and off, so last night I destroyed it.
It had a very, very hard thick partially irregularly coiled and ridged tube that was 5-6mm at its largest, the aperture. The tube was so hard I could only break it apart bit by bit with a pair of needle-nose pliers. I extracted what seemed to be all of the soft body, pictured and annotated below, although I can't guarantee the body is 100% complete. The worm? was bilaterally symmetrical and unsegmented. What I presume to be its 'head' had two pairs of extendable but fairly short unbranching tentacles (unlike feather-dusters), a small eyespot at the base of each of the caudodorsal paired tentacles, possibly a pair of thin extendable petal-like flanges, a rostral-most crystal-clear midsagittal discoidal suction cup-shaped structure (possibly an operculum?), and what seemed to be another round midsagittal structure dorsal to that that might have been its mouth. Caudal to all these, the 'head' was swollen dorsally, bilaterally concave ventral to that swelling, and with wide bilateral ridges ventral to that. A collar separated the head and body.
I could be convinced that this was some kind of giant vermetid, but if it was then it was honk'n BIG and I should have entered it into a competition before I flushed it down the drain. Hopefully, that was the end of that.

 

[Maritimer]

Looks like a vermetid to me ... probably a pro wrestler after the lights go out, though.

~B.

 

[damsels are not mean]

Looks like a big vermetid to me. How thick? There is one in the back of my tank with a pencil sized tube. I left it there since it doesn't seem able to reproduce on its own and is therefore harmless.

 

[ChiCity]

It had a very, very hard thick partially irregularly coiled and ridged tube that was 5-6mm at its largest, the aperture. The tube was so hard I could only break it apart bit by bit with a pair of needle-nose pliers. I extracted what seemed to be all of the soft body, pictured and annotated below, although I can't guarantee the body is 100% complete.

The worm? was bilaterally symmetrical and unsegmented. What I presume to be its 'head' had two pairs of extendable but fairly short unbranching tentacles (unlike feather-dusters), a small eyespot at the base of each of the caudodorsal paired tentacles, possibly a pair of thin extendable petal-like flanges, a rostral-most crystal-clear midsagittal discoidal suction cup-shaped structure (possibly an operculum?), and what seemed to be another round midsagittal structure dorsal to that that might have been its mouth.

Caudal to all these, the 'head' was swollen dorsally, bilaterally concave ventral to that swelling, and with wide bilateral ridges ventral to that. A collar separated the head and body.
I could be convinced that this was some kind of giant vermetid, but if it was then it was honk'n

this… description of… a vermetid… is… wild.

 

[Peter Houde]

Looks like a big vermetid to me. How thick? There is one in the back of my tank with a pencil sized tube. I left it there since it doesn't seem able to reproduce on its own and is therefore harmless.

I considered keeping it in the QT, but I could only get at it piece by piece and I seemed to have killed it in the process. Just the same, nothing but nothing seems to be incapable of reproducing uncontrollably in my tank, and not knowing what it was...

 

[Llyod276]

Man, I'm so jealous!!!! If you actually have a microscope. And the latest edition of invertebrate zoology. Mine is from the 70s and of the Mediterranean. Got me green as a dollar bill rn!

Isn't it odd that most of the fish trafficking happening from lfs come from the tropics? Like anybody ever heard of an Greenland tang or artic angel??? Hell, the Mediterranean is tropic/subtropical, so why not??

 

[Peter Houde]

Man, I'm so jealous!!!! If you actually have a microscope. And the latest edition of invertebrate zoology. Mine is from the 70s and of the Mediterranean. Got me green as a dollar bill rn!

Isn't it odd that most of the fish trafficking happening from lfs come from the tropics? Like anybody ever heard of an Greenland tang or artic angel??? Hell, the Mediterranean is tropic/subtropical, so why not??

Actually, I don't have a text of invert zoology. Perhaps I should get one. I'm forever trying to figure out what turns up in my tank.

 

[Llyod276]

That's is not a vermitid snails. Though. That appears to be a type of nudibranch or slug of some kind. Unless its a giant type of vermitid and doesn't have shell. Vermitid that I have and seen, are small like 4-5mm across with a shell that looks like a dog turd at the base, the tube can reach quite a ways. Had one on the bottom of my trachy and the opening tube was about an inch long...

 

[ISpeakForTheSeas]

That's is not a vermitid snails. Though. That appears to be a type of nudibranch or slug of some kind. Unless its a giant type of vermitid and doesn't have shell. Vermitid that I have and seen, are small like 4-5mm across with a shell that looks like a dog turd at the base, the tube can reach quite a ways. Had one on the bottom of my trachy and the opening tube was about an inch long...

It's a giant vermetid - the shell is in the first pic (the OP talks about breaking the tube with pliers and pulling the snail out in the opening post), and some vermetids actually get quite large (though they're not nearly as common as the smaller ones in the hobby).