What kind of worm is this and what is it excreting?

[lagatbezan]

while cleaning my tank tonight I noticed an explosion of these worms and they are releasing this pinkish substance. What are they and what are they excreting? Are they bad?
Thanks in advance.

 

[Maritimer]

It's a bristleworm, a fine member of your cleanup crew (so long as their populations don't get out of control, and you don't try to pick one up - those bristles are like fiberglass insulation!).

The stuff coming out of it ... I would guess gametes? You may have little bristles on the way.

~Bruce

 

[Reefer Deez]

It's a bristleworm, a fine member of your cleanup crew (so long as their populations don't get out of control, and you don't try to pick one up - those bristles are like fiberglass insulation!).

The stuff coming out of it ... I would guess gametes? You may have little bristles on the way.

~Bruce

You said it right that’s what they are and they are great clean up crew mates. My Nasir had a really bad case if them though he must of had hundreds that would come out at night but he never had algae. It finally got to be to much for him he ended up getting all new rick and sand.

 

[lagatbezan]

Thanks for the replies. I have color changing led lights so I put it on red and boom worm explosion
Yeah they look like bristle worms. I also saw a couple of what looks like bearded fireworms and they were like 2-3" long. Are they also beneficial?

 

[Maritimer]

Their sting would be rather more painful ... but actual fireworms seem to be pretty rare.

~Bruce

 

[lagatbezan]

Their sting would be rather more painful ... but actual fireworms seem to be pretty rare.

~Bruce

How can one tell the difference between the two? Some claim bristle worms are beneficial while fireworms as horrors.
Here is a recent video. Not sure which they are. They must have been in my tank for over +8 years since it's a fowlr and No corals or live rocks/sand been added since. Sorry for the crappy video.

 

[Maritimer]

Those might well be fireworms, as they don't look like the common bristles in my tank. @Tahoe61, @KJ, @SAPPER - any opinions on these extra-fuzzy worms?

(Aside from "Can't touch this", of course!)

~Bruce

 

[Tahoe61]

https://www.lionfishlair.com/hitchhikers-guide/

Polychaete.

 

[SAPPER]

looks like a fire worm to me i would get rid, and i am a fan of bristle worms just not those. They are Amphinomidae worms and they eat soft and hard corals. The worst and most common that i have seen people post as a hitchhiker is Hermodice Carunculata. But they also feed on clams, shrimp, mysid, mussels etc... when i was last diving off the Spanish island Majorca i watched one ripping in to an urchin.