Strange things in my aquarium

Sorry, guys that I post here, but I don’t even know where to ask what the sh*t happens in my aquarium! Recently there appeared these strange things (I hope I will be able to upload the picture)

Suggestions?

1 Like

But that’s a beautiful creature. A Bearded Fireworm, you don’t have the chance to see it often. I heard that they aren’t beneficial for your aquarium tho. A bad wolf hidden in a sheep coat isn’t it?

I agree - that’s a pretty beautiful little bastard. I get it that they are harmful for the aquarium but if you put more of them in the same aquarium, would they be able to live together? Without preys I mean. Will they hunt each other? I heard that there are beneficial worms also, from the same family. I found some nice pictures of them on https://arcreef.com/bristle-worms/bristle-worms-fireworms/

Really strange things.