Jelly fish growing in my tank??

Avelino Alicea · May 27, 2018

So, I'm going to try and post pics later because in having a hard time getting good photos of this due to the lighting in my tank but here's what I've noticed in my main tank.

In the past few weeks my tank has been growing what at first appeared to be long tentacle anemones. The live rock has a bunch of them all over. One day, I noticed one of these "anemones" had what it appeared to be a jelly fish attached to it.

I'm the course of a few days after a noticed this jelly fish had detached and was freely swimming around until it ended up in the filter sock. I looked back and found 5 of these jelly fish like critters.

Is it possible that this is what is going on in my tank? Am I growing jelly fish on my tank? Has anyone else seen this before?

EmdeReef · May 27, 2018

Try googling “hydroids” and see if it looks like it? Jelly fish is less likely but when you post pics it’ll be easier to ID.

Avelino Alicea · May 27, 2018

Yeah, I just looked at the definition, and some pics, but this is not what I have. I will try and get better pics. These guys are pretty fast once they detach and they definitely have a jelly fish behavior when they're swimming around. This is the first time I've ever had this in any of the tanks I've ever had.

EmdeReef said:
Try googling “hydroids” and see if it looks like it? Jelly fish is less likely but when you post pics it’ll be easier to ID.

ArowanaLover1902 · May 27, 2018

They don't sound good, you'll probably want to get rid of those. With pics maybe someone can id. Try posting in the hitchhikers section

Avelino Alicea · May 30, 2018

ArowanaLover1902 said:
They don't sound good, you'll probably want to get rid of those. With pics maybe someone can id. Try posting in the hitchhikers section

I can't seem to be able to attach a video from my phone, but here's a photo. Is there a way to either copy or move this thread to the hitchhikers section

Michael Llabona · May 30, 2018

Unless I'm missing it completely... The thing in the middle looks like a tube worm/feather duster. They are filter feeders. I believe they are harmless. If you do not like them, some wrasses will eat them

Avelino Alicea · May 30, 2018

Michael Llabona said:
Unless I'm missing it completely... The thing in the middle looks like a tube worm/feather duster. They are filter feeders. I believe they are harmless. If you do not like them, some wrasses will eat them

It's not a feather duster. I wish the pic was clearer. I can tell it is a jelly fish, the picture is from just before it breaks off and starts swimming. I'll try to take another pic

Avelino Alicea · May 30, 2018

Avelino Alicea said:
It's not a feather duster. I wish the pic was clearer. I can tell it is a jelly fish, the picture is from just before it breaks off and starts swimming. I'll try to take another pic

kashman100 · May 30, 2018

There are different kinds of hydroids. Google hydroid jellyfish and see if the videos are what you are seeing

Dennis McGrath · May 30, 2018

I don't know what it is, but it sure doesn't look like a jellyfish.

Sallstrom · May 30, 2018

It sounds like some kind of a jellyfish, yes. Their life cycle is:
Polyp - they live a life as an anemone, attached to a hard surface.
Strobilation - the polyp starts to form many small jellyfish, looks a bit like plates stacked on top of each other. The small jellyfish on top will eventually release and start swimming.
This stage is called ephyrae. The ephyrae looks a bit like starfish, with five arm. But is swimming.
Next stage is what we know as a jellyfish, the medusa stage.

Try to get a better picture, maybe it's possible to ID the species!

And I don't think you need to worry they will take over your tank, I don't think they will survive for long if you have a regular reef tank will lots of rocks and stream pumps.
If you want them to survive you'll probably need a Kreisler aquarium.

/David