# Pond Water Organism ID



## phender (Jan 9, 2009)

OK, so I am cheating a little bit as this was not found in a viv's pond water, but in a large creek at a golf course. I collected a water sample for a microscope lab where the students were IDing organisms in the "pond water". 
Most of the stuff was pretty standard until someone saw what looked like a stack of cells (or tiles) that would spread itself out into a shallow stair like configuration (almost a straight line) and then retract into a stack again. Sometimes the bottom tile would stay stationary with the top tile moving away, other times the middle tile would stay stationary with the top and bottom tiles moving in opposite directions. 
I've included a video that was taken with a cell phone at 100x magnification. Obviously its not very good, but it does show the motion out and then back into a stack again.
Any of you brilliant Biologists have an idea what it is?
http://vid221.photobucket.com/albums/dd234/phender_01/Unk%20Pond%20Org%20-%20Broadband_zpsq6ohivus.mp4


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## phender (Jan 9, 2009)

Nobody has a clue on this thing?


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## kimcmich (Jan 17, 2016)

Greetings,

The form and movement suggest an annelid - perhaps one of the interstitial species. What's the size of the area we're looking at in your vid?

-|<ipp


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## phender (Jan 9, 2009)

kimcmich said:


> Greetings,
> 
> The form and movement suggest an annelid - perhaps one of the interstitial species. What's the size of the area we're looking at in your vid?
> 
> -|<ipp


Its a standard "high school" microscope at a magnification of 100x.


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## kimcmich (Jan 17, 2016)

Greetings,

Reviewing your vid, I think the size is too small for an annelid. The movement suggests a amoeboid organism - but that is a very vague guess. If you had clearer detail of the full organism unobscured by the surrounding detritus it would help. It's hard to see if the extended arm is only a pseudopod or an entire organism...


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## phender (Jan 9, 2009)

kimcmich said:


> Greetings,
> 
> Reviewing your vid, I think the size is too small for an annelid. The movement suggests a amoeboid organism - but that is a very vague guess. If you had clearer detail of the full organism unobscured by the surrounding detritus it would help. It's hard to see if the extended arm is only a pseudopod or an entire organism...


I am pretty sure it is the entire organism. The first time I looked at it wasn't as obscured and the bottom moved in the opposite direction from the top with the middle anchored.


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## CharlesT0271 (Jan 24, 2017)

Looks like a stentor to me.


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## phender (Jan 9, 2009)

CharlesT0271 said:


> Looks like a stentor to me.


Based on what?

Stentors are trumpet shaped ciliates that have cilia at their trumpet end that beat so hard they tend to create a current around their mouths that is pretty obvious in a microscope. I couldn't see any cilia on this critter. Sentors can expand and contract, but I have never seen one with the "tile" effect like this organism.


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## kimcmich (Jan 17, 2016)

Phender,

When the organism is extending, I see what _might_ be a crown of cilia - it's at the very limit of the resolution of this video. The extension and contraction look similar to stentor - but I also agree the distortion of the "head" shape when it contracts again does not look very stentor-like.

The 'scope was not the best and the video is fairly low-res, so I don't know if we'd be able to pick-out the cilia moving even if they are there...


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## Jermander (Mar 12, 2014)

I agree with the stentor theory. The cilia won't always be visible or may be barely visible.

http://media.gettyimages.com/videos/stentor-coeruleus-micrograph-video-id472944267?s=640x640


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## CharlesT0271 (Jan 24, 2017)

I've been trying to remember the dang name all night. But there is a species of stentor with lateral lines and the cilia is like a flat flap at the end. I was thinking also maybe the angle was a trick on the eye making the end appear flat. There isn't enough detritus around its end to really see cilia movement. At 100x magnification the size is about correct for a stentor. Stentors can move very fast so it does have more positives going for it being a stentor than something else. But this is just based off high school teachings that I actually do remember I'm no micro biologist.


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## CharlesT0271 (Jan 24, 2017)

How about lacrymaria or Spathidium vermiforme. Or the Posibility or the stentor splitting at the end creating the odd head in the video.


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## phender (Jan 9, 2009)

What's not being accounted for in the stentor theory is something that is difficult to see in the video, but was readily visible actually looking through the microscope. When contracted the organisms looked like a stack of tiles. When it extended it looked like the tiles were being pushed similar to flattening out a deck of cards on the table with each card still overlapping the other just a little bit. It would then contract back into its original stacked card position.
Its weird that this thread resurfaced because after forgetting about it, I had just sent the video to a pond organism expert, but have yet to hear back. The biology dept. at a local major university could not ID it.


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## CharlesT0271 (Jan 24, 2017)

Its interesting for sure.


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## kimcmich (Jan 17, 2016)

Stentors have multiple nuclei that can be linked in a chain. The attached illustration shows this - perhaps these are the "tiles" in the stalk.

Having reviewed a bunch of google images of extended stentors (including ones that seem to have flat heads), I lean more and more toward that id.


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## phender (Jan 9, 2009)

I found it. The wildlife dept. guy got back to me and said he thought it looked like a colonial diatom that slides back and forth on its frustules (shells), but he is in Panama on vacation and google wasn't helping him. (he was spelling frustules wrong)

That sounded right to me because of the golden color and the tile like appearance.
So... my search took me a while and I actually kind of just got lucky, but the organism is indeed a colonial diatom in the genus Bacillaria.
Here is a pic


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## CharlesT0271 (Jan 24, 2017)

Nice! Now the hunt is over. What strange behavior for a diatom.


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## kimcmich (Jan 17, 2016)

@Phender

Finally! With the visual template of your Bacillaria images (sadly no videos on google) I was able to see the tiled effect you speak of. 

I captured a still from your video at the end of the colonial contraction and could finally see that we're looking at the end of the "ribbon" of diatom cells - the distal cells having already slid back beside each other to form the curved/slightly-coiled ribbon structure. Your video also shows a more natural color for the cells (golden-brown) than the google image (which may have been taken against a blue background?)

A little phylogentic trivia: Diatoms are part of the Heterokonts. Not all Heterokonts have chloroplasts, but those that do have chloroplasts with _quadruple_ membranes. This means a Heterokont ancestor "swallowed" another protist that had its _own_ chloroplast whose ancestor had been swallowed by that protist! Dizzying double endosymbiosis!


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## Broseph (Dec 5, 2011)

phender said:


> I found it. The wildlife dept. guy got back to me and said he thought it looked like a colonial diatom that slides back and forth on its frustules (shells), but he is in Panama on vacation and google wasn't helping him. (he was spelling frustules wrong).



Sounds frustulating 



Sorry, I couldn't help it


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## phender (Jan 9, 2009)

Broseph said:


> Sounds frustulating
> 
> 
> 
> Sorry, I couldn't help it


That was awesome. Nothing to be sorry for.


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