help - is this harmful?

[dnsfpl]

what is this?
will it harm my octo?
must i remove it?

thanks

http://i41.*******.com/awoqxf.jpg

[ludnix]

It looks like a feather duster. If it's stationary but will contract into a hard tube and slowly come back out after a while its most likely a feather duster.

These are harmless filter feeders but are often eaten by fish which causes them to usually grow in out of sight areas or places fish cannot reach.

[dnsfpl]

thanks a million