Interesting picture of feather duster and question.

[Wampatom]

I took this close up of a feather duster and noticed an umbrella like structure associated with it. The feather duster is about 2 mm across. I can just barely see the umbrella structure with my naked eye. It is so small it may be common and I have simply not seen enough detail to really consider it. Is this part of this type of feather duster, or is it another organism?

 

[Anonymous]

Wow grat pic Tom.

No idea on the small cup shaped organism but I am going to say by looks it' some kind of commensal/parasitic/opportunistic cnidarian.

 

[investigator1]

My guess is that it is a baby newly growing.

 

[Anonymous]

Cool pic, and no clue!

HD

 

[Wampatom]

My guess is that it is a baby newly growing.

Interesting idea. I will keep my eye on it. It has not changed since yesterday.

I was wrong about the size. It is about twice as big as I remembered. The feather duster covers about 4mm.

 

[John_Brandt]

Hi Tom, fancy meeting you here

I am going to lose sleep over this one! But first I have to say that your photos are always very impressive. I just love them!

What the heck is that thing? Could you cause the fan worm to retract into its tube and then take another photo, please?

Many of these fan worms have an operculum which acts as a "trap-door" when they retract into their tube. Sometimes the operculum has an appendage attached to it, often looking like a little branched tree. But I've never seen that appendage look like this, nor in this position when the worm is extended. But I think this is not part of the worm.

This thing has radial symmetry and a stalk, which does suggest a cnidarian. Where does that stalk lead to? Where is it attached?

 

[Chucker]

The "umbrella thing" is part of the worm itself. Think larger, and look at a fanworm you'd buy at the LFS.... you'll see the same structure. It is indeed an operculum (as JB mentioned), and is composed of numerous setae. The structure is found in serpulid and spirorbid worms (which is what your little guy is), but not in sabellids.

 

[John_Brandt]

Good call Kevin. I'm with you, man. Tom, can you confirm that it is the worm's trap-door?

Look at this serpulid and its operculum...

http://www.underwater-photos.com

 

[Wampatom]

Tom, can you confirm that it is the worm's trap-door?

Yes. Unbelievable. This must be how Dr. Suess got the ideas for his sketches.

I have attached a sequence of the worm coming out. After tapping the glass, I had to wait for 5 minutes before he ventured out.

 

[Wampatom]

I guess I can only post 3 images at a time. Here are the next 3.

 

[Anonymous]

Man those are some nice shots.

 

[Anonymous]

Absolutely Gorgeous Shots!

 

[Anonymous]

Are you able to get those sequences with a digital camera, or is it a standard 35mm SLR? I saw that thing and was reminded of a flower's stamen or pistil.. thought it could be a worm's sexual organ, but Chucker's the mayuhn.

 

[Anonymous]

that is just the coolest thing i have ever seen. i can't remember the last time i sat glued to the monitor with my mouth wide open. thanks for sharing!!!

runs off to find her magnifying glass to look at her wormies...

 

[Wampatom]

Thanks. I am still amazed what I find in a reef tank—and how much some people know about them—Chucker, John.

I used a digital Nikon D100 to take the pictures. It closed too fast to get any pictures then, so I took them as it was re-extending. I had to turn the auxiliary focus light off because every time I tried to take a picture it closed up again. It extended quite slowly so it was easy to take them.

 

[Anonymous]

So that Nikon can take sequential pix fairly quickly, then?

 

[Chucker]

Actually, I thought John had the right idea... I just confirmed it by looking it up in Ruppert and Barnes - Invertebrate Zoology.