What is this?

[Agiron86]

It recedes back into the "tube" like a feather duster does?

I also have white "dots" randomly on the back of my aquarium, I am thinking they're are copepods. I asked the girl at the lfs and she said they might be a form of filtering snail.

 

[Dsnakes]

Your white dots, if stationary, are likely spirorbid worms. Tiny feathers from them? That looks like a small feather duster as well.

 

[Big G]

Hard to tell from your picture. Here's a link where you can eyeball your critter. Hope this helps! Cheers!
https://www.lionfishlair.com/hitchhikers-guide/

 

[Crabs McJones]

I'm with @Dsnakes looks like feather duster

 

[ReeferMaddness843]

The white dots, are they coiled? If so, I’d lean towards spirorbid worms.
The one in the pic I’m not sure on off hand.

 

[Agiron86]

I’m trying to get a better pic, of the “feather duster”

I can’t tell if they’re spiraled, if they are are they “bad”

 

[Crabs McJones]

I’m trying to get a better pic, of the “feather duster”

I can’t tell if they’re spiraled, if they are are they “bad”

Generally not. They can multiply pretty quickly though if enough food is available.

 

[Dsnakes]

I’m trying to get a better pic, of the “feather duster”

I can’t tell if they’re spiraled, if they are are they “bad”

Not at all, just filter feeders. You can scrape them off when cleaning the glass if you'd like. I leave them on the back and scrape them when cleaning the other 3 sides.

 

[Agiron86]

Generally not. They can multiply pretty quickly though if enough food is available.

What is their food?

 

[Dsnakes]

What is their food?

Just suspended micro particulates in the water I think.

 

[Dsnakes]

I've got Vayssierea Felis nudibranch multiplying in my tank now. They eat the spirorbid worms. Cool little orange slugs. Very small as well.

 

[Agiron86]

I've got Vayssierea Felis nudibranch multiplying in my tank now. They eat the spirorbid worms. Cool little orange slugs. Very small as well.

Does anything eat the nudibranch?

 

[Dsnakes]

Does anything eat the nudibranch?

I'm sure most any wrasse would pick them off.

 

[Agiron86]

Would a wrasse eat the spirorbid worm as well

 

[Dsnakes]

Would a wrasse eat the spirorbid worm as well

Most likely not.

 

[Agiron86]

Most likely not.

Is there anything that would?

 

[Agiron86]

 

[Maritimer]

That's a feather-duster worm. Absolutely harmless, attractive filter-feeders.

I love pointing them out to visitors, who never would have guessed that a worm could be beautiful!

BTW, there's a spirorbid worm below and to the right of the duster . . .

~Bruce