I've just been doing my normal weekly gravel vacuum and hoofed up this little beauty. Would you say it's a bristleworm? If so, should I put it back in or leave it out of the tank? How come I've been vacuuming the gravel weekly for well over a year and never seen one?
Yes it's a fresh water bristle worm. How big is it? It looks quite large and they can be a tad predatory if they get big. Might go for small fry, shrimplets etc.
If you don't mind it and as you haven't anything in there it might go for, I'd put it back. With adult fish it'll be harmless and help out a bit with cleaning at the bottom