I love feather dusters and never had them hitchhike so this is a really cool find. they're pretty good filter feeders but if it is necessary the easiest way is to superglue they're openings.
These are colonial hydroids and should be removed by any means possible.
These are not hydroids, they are nothing more than run of the mill feather dusters and you can tell by the tubes.. hydroids have very short tubes and will not break off like these guys they’re almost rubbery and a pain to remove…
wut
There are many types of colonial hydroids, and some very closely resemble the OP's photos. I hope the OP has feather dusters but IME, those look like the hydroids that took over a tank -the only tank I've ever had to break down over a pest.
Again, there are many different types and they can look just like the ones the OP posted.wut
Those are calcium tubes, I've seen hydroids and those are not hydroids. the feathery part can look like a hydroid but there be calcium tubes there. tbh, I thought polythoas were hydroids!
