ID? (solved)

I don't know if this is the correct section to post. If it isn't can mods move it to the correct section thanks.

So I've got 2 fairly new setups at the moment that both share the same-looking microorganisms. I've had microorganisms pop up many times before when I've set up new tanks (zoothamnium arbuscula previously I think). However, these are a little different in size and shape. Glass is covered in them. The pictures were very hard to get! So closer-ups probably aren't doable. A handheld magnifying glass and a DSLR camera don't work very well together ID?


@Seisage I remember an older thread where you discussed Obelia I think.. it seems you are knowledgeable in this area. Do you have any idea what these are? And if they pose a threat to any other living organisms? TIA

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I've sent some pictures to Let's scope it out to see if he or someone he knows can help ID them

Well, that was quick got an answer already!

"A giant population of Stentors. Completely harmless single celled giants filtering the water"

MattW said:

A giant population of Stentors.

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Stentors have always bothered me as being a single celled animal that gets enough to see with the naked eye lol. A long long time ago I was in a biology class that had mail ordered a bunch of single celled critters in jars to look at under the microscope, and I took a sample from each jar and put it in a bag of water to take home to look at on my own time. It was a massacre. The Stentors ate absolutely everything in about two days, including the amoebas that were initially the biggest thing in there, and those Stentors eventually got as big as yours. Unfortunately I later learned they don't last long if there are any larger organisms in the environment.

Do you happen to know where yours came from?

Cool! And now I have a new favorite youtube channel...

Donya said:

Do you happen to know where yours came from?

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There are two possibilities I can think of.
Originally I first saw them in a 5L food container I used as plant storage with an airstone. I moved the plants and water into a 10L tank that I'm now using for my fry and daphnia colony.
I've never seen them previously so my guesses would be when I introduced the bag of live food (daphnia) or when I introduced my new shrimp in my 60L and some of their water got taken out to be put in the 5L when I set it up.

Actually having a closer look at the 60L they are all over the glass aswell

WhistlingBadger said:

Cool! And now I have a new favorite youtube channel...

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I've been watching his streams for a while now, and it's a really good watch. I originally found out about him from this forum actually, a thread from a while back.

Found it! - Thread

MattW said:

Originally I first saw them in a 5L food container I used as plant storage with an airstone. I moved the plants and water into a 10L tank that I'm now using for my fry and daphnia colony.
I've never seen them previously so my guesses would be when I introduced the bag of live food (daphnia) or when I introduced my new shrimp in my 60L and some of their water got taken out to be put in the 5L when I set it up.

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Daphnia are filter feeders and Stentors are also filter feeders, so the same water could grow both - althogh I'd think the daphnia would eventually eat the stentors. Maybe they're relatively safe from the daphnia if they get big and stay attached to surfaces.

MattW said:

Actually having a closer look at the 60L they are all over the glass aswell

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Wait, your shimp aren't eating them? I would've assumed they'd vanish pretty fast in the attached state if there were shrimp in with them.

Donya said:

Daphnia are filter feeders and Stentors are also filter feeders, so the same water could grow both - althogh I'd think the daphnia would eventually eat the stentors. Maybe they're relatively safe from the daphnia if they get big and stay attached to surfaces.

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Thats interesting. The majority of daphnia in the fry tank are about the same size as the Stentors at the moment. I only added a handful of adult daphnia when I set up this tank, which have now bred. I have noticed they seem to congregate in the top 1/4 of the tank which I'm assuming is because of increased oxygen levels in that area of the tank? Or water movement? I forgot to mention also I am adding regular amounts of infosuria from my culture as well to this tank as a food source for the fry.

They seem to love this area of the tank.

Donya said:

Wait, your shimp aren't eating them? I would've assumed they'd vanish pretty fast in the attached state if there were shrimp in with them.

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There are certainly less numbers of them in my 60L compared to the fry tank but still a decent amount. I have scraped the glass a few times now and they always pop back up a few days later. Perhaps the shrimp don't like the taste of Stentors at the moment?

edit - @Donya Do you know of any cheap microscopic cameras? I would love to see them in much more detail