ID Please. Are these worm casings?

[mike550]

So I’m going through and reworking my tank and the scape. As I was removing rock, I found many of them have these white tubule like growths. They are hard and seem to be calcifield or something. Would appreciate knowing what they are and what critter (?) might have made them. Thanks in advance!

 

[ISpeakForTheSeas]

So I’m going through and reworking my tank and the scape. As I was removing rock, I found many of them have these white tubule like growths. They are hard and seem to be calcifield or something. Would appreciate knowing what they are and what critter (?) might have made them. Thanks in advance!

To my knowledge, those are feather duster worm tubes.

 

[mike550]

To my knowledge, those are feather duster worm tubes.

Thanks. Too bad I didn’t have that many feather dusters … that might have been cool.