What on Earth is this???

[F i s h y]

Feather duster worms are known to drop their crowns and leave the mucous membrane tube they live in. what we commonly see is not the actual worm but the home it builds for itself. my guess is that your worm has abandoned its tube and lost its crown. with proper water parameters i have seen them regrow both. but it should be in the sand for this. Google and see if you can find any examples of this.
Have you seen your feather duster since this started?

 

[Kasrift]

It's a Fuzzy Chiton!!! Good guy, great at scouring the rocks!! @littlefoxx I bought one from reef Cleaners for 6$ a chiton! They are great.

Fuzzy Chiton*

Resides : Rocks and glass Consumes : Hair Algae, Cyanobacteria, Diatoms and Turf Algae Max Size : 2 or 50mm Origin : Caribbean Availability: Weekly Warnings : Not...

www.reefcleaners.org

 

[F i s h y]

Featherdusterb broken in half

Hey everyone i just got a new feather duster for my tank and the guy at the fish store was a little rough with him i think and riped the tube from the bottom right before the part with all the rock on it. What is the best thing to do right now? is it dead? the feathers are still there but idk...

www.reef2reef.com

Feather Duster Out of Shell

Hi, one of my feather dusters jumped out of his shell last night. Not sure why, as he was already attached and the three other dusters near his vacated shell still seem very happy. Anyhow, the free worm appears to be trying to reform its shell (good), but other fish have started nipping at it...

www.reef2reef.com

 

[F i s h y]

Could also be a peanut worm if it isnt your feather duster.

 

[A Young reefer]

some sort of sea cucumber?

 

[littlefoxx]

It's a Fuzzy Chiton!!! Good guy, great at scouring the rocks!! @littlefoxx I bought one from reef Cleaners for 6$ a chiton! They are great.

Fuzzy Chiton*

Resides : Rocks and glass Consumes : Hair Algae, Cyanobacteria, Diatoms and Turf Algae Max Size : 2 or 50mm Origin : Caribbean Availability: Weekly Warnings : Not...

www.reefcleaners.org

Yeah its not that, this is for sure a worm. I do have chitons in my other tank though

 

[Dbichler]

My vote is peanut worm

 

[Mr_Knightley]

I'm still betting on a sea cucumber or Sipunculid worm.

 

[ISpeakForTheSeas]

So I came home and he has extended some. Has a white circled mouth. Here are pictures

Does it have any tubefeet? (I'm assuming not, but I figured I'd ask).

If not, an unhappy feather duster isn't a bad guess, and Sipunculids (Peanut Worms), Echiurans (Spoon Worms), and Priapulids could be potential candidates too.

 

[littlefoxx]

So Ive seen my feather duster, he is in his tub and extended, unless there was more than one in the tube?

 

[Tired]

If more than one was in the tube, you would have seen more than one crown. Though I suppose maybe this could be a broken-off piece; how does it move around when uncurled? Does it seem to have any purpose, or does it just writhe?

It's not a chiton, though it did look kinda like one in the first post.

 

[Kasrift]

Yeah its not that, this is for sure a worm. I do have chitons in my other tank though

Just read through the second page, and yeah it extends so it's something else. The photos on the first page made it look like one though with the "plating" look as it was pulled in.

Stringy mouth side like you mentioned makes me agree with others that have said sea cucumber.

 

[littlefoxx]

If more than one was in the tube, you would have seen more than one crown. Though I suppose maybe this could be a broken-off piece; how does it move around when uncurled? Does it seem to have any purpose, or does it just writhe?

It's not a chiton, though it did look kinda like one in the first post.

It chills for the most part but at night it kinda extends and moves around like its looking for food, but its not fast and really only moves the extended part of its body through the water.

 

[littlefoxx]

So Im wondering if its a sea cucumber. I looked them up and it has like a white long thing it extended last night for a small amount of time like some pictures.

 

[19Mateo83]

I couldn't resist…