[untamed]

Originally Posted by SeaHorse_Fanatic

Small ones are not bad. Big ones may attack livestock in your tank. I had a huge one attack and bite a chunk out of one of my seahorses. Tore the tank apart to get that sucker out but still lost the seahorse due to its wounds. Large bristleworms also mean high chance of bristles in your fingers when you more rock or corals around. Hate that feeling so I remove the large ones.

An overabundance of bristleworms means you're overfeeding. Just a few is good for your tank as detrivores.

Anthony

That sounds like a eunicid worm...very different that what most of us call "bristleworms". Eunicid's have nasty jaws and are very, very fast movers.