Identification please

flyer2o12 · Post by **flyer2o12** » Wed Apr 17, 2013 4:00 am

Can someone please identify these organisms?

http://www.flickr.com/photos/38484518@N ... hotostream

There were extracted from near the ponds surface here in Ireland.

Please excuse the awful quality of the movie, we do not have the appropriate adapters to mount the DSLR to the microscope.

Bruce Taylor · Post by **Bruce Taylor** » Wed Apr 17, 2013 3:40 pm

At this magnification, it is difficult to say more than "speedy little ciliates."

To me, they have a Prostomatean look (the mouth seems to be apical, and the swimming style & big vacuole remind me of certain Prorodontida).

flyer2o12 · Post by **flyer2o12** » Thu Apr 18, 2013 10:32 am

Hi Bruce thank you for your response. Those creatures you mentioned look like Coleps. These organisms definately do not look like Coleps though. I will post another movie soon of better quality.

Bruce Taylor · Post by **Bruce Taylor** » Thu Apr 18, 2013 8:59 pm

flyer2o12 wrote:Hi Bruce thank you for your response. Those creatures you mentioned look like Coleps. These organisms definately do not look like Coleps though. I will post another movie soon of better quality.

Prostomatea is a large group of ciliates, and few of its members resemble Coleps, with its lovely costume of epiplasmal platelets.

I was thinking more of certain smaller members of Prorodon or Holophrya (or related genera with apical cytostomes).

Perhaps a closer view of the oral structures will help narrow things down a bit.

flyer2o12 · Post by **flyer2o12** » Fri Apr 19, 2013 4:40 am

Will scanning electron microscopy help you to id them?

Bruce Taylor · Post by **Bruce Taylor** » Fri Apr 19, 2013 7:08 am

Anything that gives a clear view of the mouth would be a start.

If it wears its mouth on one side, we're looking at a whole different class.

flyer2o12 · Post by **flyer2o12** » Mon Apr 22, 2013 3:15 am

Hi Bruce, I have uploaded two new movies of much better quality than the previous one and I plan on doing some scanning electron microscopy of them tomorrow. http://www.flickr.com/photos/38484518@N ... hotostream

Bruce Taylor · Post by **Bruce Taylor** » Mon Apr 22, 2013 5:25 am

Well, there are certainly a lot of them.

I'm looking forward to the electron micrograph!

I dug into your photostream a bit. The creature you recorded on March 07 is the same as the one you filmed on March 03: Stylonychia, probably S. pustulata. The caudal cirri are briefly visible at 0:53 of the 07 video.

A video, showing the anatomy of a Stylonychia from another Canadian pond: https://www.youtube.com/watch?v=rsjMSXarR3o Important groups of cirri are labelled.

The creature you recorded on March 20 -- round in cross-section, with big macronucleus, lateral cv and pigment spots -- might be Ophryoglena atra. Unfortunately, I was unable to find the mouth.

Ecki · Post by **Ecki** » Mon Apr 22, 2013 12:56 pm

Will scanning electron microscopy help you to id them?

Probably not! After sputter coating you can not detect anything inside the ciliate - thus many ciliates can not be properly identified just with a SEM image. You need to make an image with a very high magnification (DIC) of the oral apparatus and identify as many features (cortex, nuclei, CVs etc) as possible.

As you have so many of those critters you can try the following:

Filter some of the water in which the ciliates are living now. Take 2 or 3 microscope slides with cavities (hollow grinding). Use a very fine pipette to take some critters out of your sample. Release them into the first slide and into the hollow. Fill it up with some of the filtered water. Observe under the stereo microscope. If there is debris with the critters, use the pipette again and transfer the critters to the next slide, fill it up with cleaned water. Repeat transferring them from hollo to hollow until you have the critters totally isolated. Then put wax or vaseline on the corners of a cover slip. Remove excess water with the pipette from the last hollow with your clean ciliates by pressing the pipette onto a spot where there are no ciliates - release the pipette. That way, the critters will not be sucked into the pipette. Remove unwanted water this way to concentrate the critters.

Now put the critters on a normal slide. Carefully attach the coverslip. You can control the thickness by using a little bit of pressure on the coverslip. Control this with the microscope. You can lower the cover slip until the critters are pretty much immobilized. You can put a drop of distilled water next to the coverslip. The wax prevents the coverslip from coming down further and you can keep this mini aquarium alive for a while.

This way you can make good photos and you can observe and note the details of your critter. Then identification is not so hard. Bruce will have a blast

Regards
Eckhard