Weird thing in water

[RobinC]

No symptoms on my fish, but I've seen weird jellyfish swimming like critters in the water (after waterchanges). I cannot take a pic, but with a little hand held microscope, it seems that the closest thing I have found trying to research is trichodina? Does trichodina swim like a jellyfish? Under my crappy hand-held, it looked like it had dual stubby tenticles spaced all the way around the circular part. Mind you it was pretty big, about 2 mm.
The sponge-filter came from my macro-algae tank and is currently in my 30g set up for breeding clowns. The macro tank is connected to my main. So whatever it is, came with the sponge when I transferred it over. Any ideas?

 

[ISpeakForTheSeas]

My first thoughts would be medusa stage hydroids. Do you have any pics of the critters in question?

 

[Sleeping Giant]

hydroids I'm thinking too

 

[RobinC]

My first thoughts would be medusa stage hydroids. Do you have any pics of the critters in question?

Cannot get a clear enough shot. Side view swimming looks like a jellyfish, with an anemone like foot, or a mushroom. Swims up and down like a jellyfish, not sideways.

 

[EricR]

Here's a short video of free-swimming stage of some type of hydrozoa from when I found some in QT one time:

 

[RobinC]

Cannot get a clear enough shot. Side view swimming looks like a jellyfish, with an anemone like foot, or a mushroom. Swims up and down like a jellyfish, not sideways.

Just watched a video of the medusa hydroid swimming, it's upside down and not jerky like mine.

 

[Sleeping Giant]

Hydroid Jellyfish

 

[RobinC]

Here's a short video of free-swimming stage of some type of hydrozoa from when I found some in QT one time:

In this video the rounder part propels it and follows, it mine, the wider part goes first not last. literally swims like this

 

[Jay Hemdal Verified Community Expert]

No symptoms on my fish, but I've seen weird jellyfish swimming like critters in the water (after waterchanges). I cannot take a pic, but with a little hand held microscope, it seems that the closest thing I have found trying to research is trichodina? Does trichodina swim like a jellyfish? Under my crappy hand-held, it looked like it had dual stubby tenticles spaced all the way around the circular part. Mind you it was pretty big, about 2 mm.
The sponge-filter came from my macro-algae tank and is currently in my 30g set up for breeding clowns. The macro tank is connected to my main. So whatever it is, came with the sponge when I transferred it over. Any ideas?

Sounds like a Medusa stage of some coelenterate to me, most likely a hydroid.

I’ve only seen Trichodina on FW fish, and they are much smaller ( < 200 micron) and I’ve never seen them free swimming.

Jay

 

[Borat]

It's a dolphin I think...

 

[RobinC]

I've seen another a month or so back, seems like I would be seeing them on my glass by now? Not sure what to do Thanks everyone, I'll be researching some more on hydroids, lol.

 

[Garf]

Like this?

 

[vetteguy53081]

Hydroid Jellyfish

Hydroid jellyfish which are short lived and harmless- just a nuisance

 

[RobinC]

Like this?

Yes! That is it! What is it? lol

 

[Garf]

Yes! That is it! What is it? lol

LOL, I’ve no idea what it is. Found it in my nearly 3 year old dry rock tank, a month or so ago.

 

[RobinC]

LOL, I’ve no idea what it is. Found it in my nearly 3 year old dry rock tank, a month or so ago.

So it's not a Hydroid?

 

[ISpeakForTheSeas]

So it's not a Hydroid?

If you can get a couple of close up, clear pictures of it (particularly of the bell/umbrella and tentacles - preferably both from the side and and looking straight on at it from the bottom/below the tentacles), we might be able to ID it.

As it stands, it is most likely (almost certainly) in one of the four following categories: Cubozoa, Hydrozoa, Scyphozoa, or Staurozoa - this doesn’t tell us much about the ID though.

 

[RobinC]

LOL, I’ve no idea what it is. Found it in my nearly 3 year old dry rock tank, a month or so ago.

Unfortunately, I have figured out that they are indeed a type of hydroid....My sponge filter is now covered in them. Clownfish breeding tank, so they get a lot of food They are very small, and can easily be overlooked.