i foudn on in my tank , its about 4 inches or longer and its about a quarter of an inch wide,

they have never hurt my fish , but i know that a octo skins is delicate and bristle worms are , well , bristley

i wouldnt expect so, they are good scavengers for an octo tank.

I had a bristle worm almost a foot long with my cuttles

unless you get a tiny baby octopus, then maybe better removing big worms to be safe

Even bigger bimacs don't seem to like the bristle worms much. My bimac would poke at a worm when she saw it and make it retreat. After she had eggs, she killed bristle worms, even large ones. I found the pieces in the tank. She must have thought they were a threat to her eggs (and I have read that bristle worms will eat eggs).

Nancy