ID for a noob, possible bristle?

[will0wtr33]

Must have hitchhiked in on my live rock, tank has been up for about 6 weeks and haven't seen this until last night. I turned on the lights in my bedroom (tank lights were off) and saw like 3 of these scurry into the rock. This one just went into the shade and chilled. Maybe a few mm long, looks like it has tiny antennae like a bug. My first thought was bristle worm, but someone told me those are usually red-ish and not black like this was. Sorry for the poor picture quality, I had to zoom to get a closer pic and my camera sucks.

 

[Lovemyreef2015]

It's really hard to tell but the mouth or head almost makes me think medusa worm. Is there anyway to catch it so you can take a better picture?

 

[will0wtr33]

I'll try. The tank has been up for a while now and I haven't seen anything like this until last night, and I spent a lot of time staring into it, haha. That one was the only one that didn't immediately scramble into holes in the rock. Fast as all hell. I'll google medusa worm and try to compare with what I saw. So much for "guaranteed cured" live rock. Found small snails, and now worms! Are they demon spawn, beneficial, or neither?

 

[Lovemyreef2015]

I'll try. The tank has been up for a while now and I haven't seen anything like this until last night, and I spent a lot of time staring into it, haha. That one was the only one that didn't immediately scramble into holes in the rock. Fast as all hell. I'll google medusa worm and try to compare with what I saw. So much for "guaranteed cured" live rock. Found small snails, and now worms! Are they demon spawn, beneficial, or neither?

If it is a medusa worm then they are beneficial.

 

[will0wtr33]

If it is a medusa worm then they are beneficial.

Thanks for the info. I just read a pretty large article on them. I think that may be it, but I feel like what I saw had the "antenna" on both sides of it. I suppose I'll try to catch one! The hunt is on =P

 

[Lovemyreef2015]

Thanks for the info. I just read a pretty large article on them. I think that may be it, but I feel like what I saw had the "antenna" on both sides of it. I suppose I'll try to catch one! The hunt is on =P

You're welcome and good luck on the hunt lol! Post pictures when you do catch it.

 

[Maggie321]

It may be an amphipod also. Look up some pictures online and see if that's it. Hard to tell from the pics.