What is it?

[florida joe]

Ok boys and girls any ideas I found this thing growing when I moved my clam (meowzer can you help) it’s hard to see with no contrast it is snow white definitely alive tubular with long feathery fringes along the tub

 

[spanko]

Is it motile? Almost looks like a feather star arm. Or Eupentacta quinquesameta a white sea cucumber.

 

[florida joe]

I don’t think so Henry it seems to be rooted in the sand and movement of the feathery parts seem to be due to water movement

 

[meowzer]

a mustache brush

 

[2quills]

Sea Pen?

 

[spanko]

Me thinks quill nailed it.