What the heck are these?!

[JCM]

Hello all,

So I am sitting in my chair enjoying a cold beverage while my lights dwindle down, when I notice something unexpected. 15 minutes before darkness, these things came out in mass! I have no idea what they are, ive never seen them before. They wiggled hard as they swam and i even noticed a few on the glass. There were dozens of them. any ideas? My fish enjoyed it.

Sorry for the horrible pics/video. I didnt have time to pull out my nice camera.

 

[JCM]

Dang it, how do i add a video? That picture is of the biggest one. Most were only 1/4" long

 

[KMench]

The first two pictures looks like a bristleworm. Does it have a bifurcation like it looks in the third picture? That would make it not a bristleworm lol...

 

[JCM]

Sorry, I'm trying to figure out how to post a video, it is more clear than the pics. They were definitely not bristleworms, most were swimming near the top, wiggling their butts to swim.

Thanks

 

[JCM]

The first two pictures looks like a bristleworm. Does it have a bifurcation like it looks in the third picture? That would make it not a bristleworm lol...

And no, that's not a bifurcation (had to look that one up). That one was on the surface and you'e seeing it's reflection

 

[andrewkw]

I think they are epitokes which is indeed part of the bristleworm life cycle.
I just experienced a similar instance in my tank last week. It was well after lights and I quickly grabbed the camera. While I didn't get any super clear closeups you can compare yours to my video.

 

[KMench]

If they were swimming, maybe it’s an epitoke? They’re the pelagic reproductive piece of some polychaete worms

 

[KMench]

Same thought I had @andrewkw

 

[JCM]

That's it!

KMench, my apologies for dismissing your bristleworm theory so quickly, I've never seen that stage before.

Thank you both for taking the time to reply.

 

[KMench]

No worries. I was thinking they were bristleworm a on the glass at first honestly I had to look up what they were the first time I saw them in my tank! Then I added some micro brittle starts and they seem to have out conpeted the bristleworms. Haven’t seen one in the DT for months now.

 

[saltyhog]

I used to have quite a few. I had a wrasse that liked to eat them. I would hold a flashlight to attract them and he would pick them off.

Fast forward to 2:56 and check out how thick they can be on the reef at night.

 

[JCM]

No worries. I was thinking they were bristleworm a on the glass at first honestly I had to look up what they were the first time I saw them in my tank! Then I added some micro brittle starts and they seem to have out conpeted the bristleworms. Haven’t seen one in the DT for months now.

Yeah, when I said they weren't bristleworms I was thinking of the pinkish/grayish ones I'm familiar with. I hope they aren't the beginning stage of some evil worm!

 

[JCM]

I used to have quite a few. I had a wrasse that liked to eat them. I would hold a flashlight to attract them and he would pick them off.

Fast forward to 2:56 and check out how thick they can be on the reef at night.

That's a cool video!

Hmm I have been wanting another leopard wrasse! I think my tank is too small unfortunately