Any idea what this is?

[Ascott7788]

I swear I didn't see this guy two days ago when I was doing some clean up and I was taking a look around just to see how things were going and found this little dude. Can't find anything on it and it looks like it's got some kind of white webbing action going on underneath as well as annoying my livestock....

 

[Fishurama]

Looks like a micro featherduster. Good filter feeders. They have some nice colors if you get the rare ones.

 

[mtfish]

Looks like a micro-feather duster to me. In my experience not a problem.

 

[Tahoe61]

The white mass is a sponge I believe.

 

[Ascott7788]

Okay, thanks for the feedback. I'll keep my eye on it to see what it does. Much appreciated.