A small unidentified ciliate

[Pat Thielen]

Hello! I took a video of this little guy on May 3rd but it's taken me awhile to get to any of the videos I shot. I don't know what this protist is; I found it very interesting that he isn't doing much of anything -- Just turning clock-wise very slowly. I did find his beating cilia very interesting, though.

As always, let me know what you think.

Plan 40 / 0.65, Bright Field, Nikon d810, Adobe Premier

[Pat Thielen]

I wonder if he somehow became stuck on the cover glass.

[zzffnn]

Nice video, Pat.

I wonder if that ciliate is paramecium bursaria.

Compressing ciliates slightly with cover slip may not he a bad thing, as that would give you minimal water gap and better image quality. Of course, the drawback is that their behavior may not be as natural - some ciliates move too fast to be recorded though, when there is no compression.

[Bruce Taylor]

No, not Paramecium bursaria. It's a hypotrich (frontal cirri and parts of the AZM are visible). Identification below subclass level is not possible, because we don't see the arrangement of cirri on the ventral surface.

When you get a ciliate pinned down like this, look at it closely at different focal planes and try to record 1) the mouth and cytopharynx, 2) the macronuclei (a two-part mac is visible here), and 3) all cirri or cilia, particularly on the ventral surface. If you can get a clear view of these things, there is a hope of a genus or species-level identification (but no guarantee...some ciliates, particularly hypotrichous ones, will require silver staining, or examination of special features like cortical granules).

Of course, a few ciliates can be identified at a glance by distinctive characters (shape, cortical pigments, etc), but there are at least 4,000 described species (and perhaps three times as many that are still unnamed), and telling them apart is not so easy.

[Pat Thielen]

No, not Paramecium bursaria. It's a hypotrich (frontal cirri and parts of the AZM are visible). Identification below subclass level is not possible, because we don't see the arrangement of cirri on the ventral surface.

When you get a ciliate pinned down like this, look at it closely at different focal planes and try to record 1) the mouth and cytopharynx, 2) the macronuclei (a two-part mac is visible here), and 3) all cirri or cilia, particularly on the ventral surface. If you can get a clear view of these things, there is a hope of a genus or species-level identification (but no guarantee...some ciliates, particularly hypotrichous ones, will require silver staining, or examination of special features like cortical granules).

Of course, a few ciliates can be identified at a glance by distinctive characters (shape, cortical pigments, etc), but there are at least 4,000 described species (and perhaps three times as many that are still unnamed), and telling them apart is not so easy.

Thanks Bruce -- I really appreciate your help in getting as close to an ID as possible with this guy. It is rather surprising that it was pinned down as other animals, larger than this one, were moving about quite freely. But yeah, somehow I think this one managed to get stuck to the cover glass somehow.

[Bruce Taylor]

It is rather surprising that it was pinned down as other animals, larger than this one, were moving about quite freely. But yeah, somehow I think this one managed to get stuck to the cover glass somehow.

It looks somewhat bloated and is probably immobile because it is dying. Anyway, this offers an opportunity to look closely at features like the cirri, by "focus diving" through the organism. Having examined a sick one closely, you can then search your sample for other specimens, to see how they look when they are fit and frisky.

[billben74]

Really interesting video.
Many thanks