Euplotes daidaleos -- Feeding behaviour clip added

Cactusdave · Post by **Cactusdave** » Tue Feb 02, 2016 1:06 pm

Euplotes daidaleos is a hypotrich ciliate related to Euplotes patella, but with lots of green zoochlorellae symbionts inside. It likes to crawl over the substrate using its cirri, which are like thickened bundled cilia, as legs. It feeds actively creating a feeding current that can be clearly seen in the second video. It seems to have quite a complicated system for accepting or rejecting potential food as in the second video what look like very palatable single celled algae (Chlorococcum?) are sucked in by the feeding current and then rejected.

Both videos are taken using DIC on a Zeiss standard. The first uses a X16 planachromat objective and the second a X40, 0.95 planapochromat. Both videos were taken with a Sony NEX 5N afocally coupled through a 45mm prime lens to a Leitz Periplan 10x18 eyepiece via filter thread couplers and the eyecup threads on the eyepiece. The camera full HD video mode was used. This sets ISO automatically and can introduce a fair amount of noise when light is low. Videos were processed with Serif MoviePlus X6. I made several efforts to balance noise reduction with blurring of detail for the higher magnification video. It's not as easy as for a still image and easy to introduce artefacts!

Euplote daideleos X16 objective

https://vimeo.com/153938104

Euplotes daideleos X40 objective showing feeding current and rejection of potential food algae.

https://vimeo.com/153751604

Jacek · Post by **Jacek** » Tue Feb 02, 2016 10:40 pm

Very nice

piermicro · Post by **piermicro** » Wed Feb 03, 2016 3:10 am

Nice.

carlos.uruguay · Post by **carlos.uruguay** » Wed Feb 03, 2016 6:06 am

Hi David.
Very good videos and very interesting information.
I thought that the cirrus of the ciliates were tough as spines.
But in this video we see a cirrus
moves when touched by a small flagellate:
https://www.youtube.com/watch?v=kSy9-6woG3I

Cactusdave · Post by **Cactusdave** » Wed Feb 03, 2016 10:49 am

Thanks very much for the comments.
Carlos -- that's a beautiful clear little clip illustrating the behaviour of the cirrus. It looks as though it moves from a joint in the base rather than bending when hit by the flagellate.

I have a short clip showing Euplotes daidaleos capturing and ingesting a small flagellate. The quality isn't brilliant, but at the beginning of the clip, the flagellate can be seen attempting to escape from the buccal cavity at the upper left of the Euplotes. At 00.13 min. it is sucked into the cytostome and disappears into a food vacuole.

https://vimeo.com/154061917

vasselle · Post by **vasselle** » Wed Feb 03, 2016 12:38 pm

Bonjour
Very nice
Cordialement seb

carlos.uruguay · Post by **carlos.uruguay** » Wed Feb 03, 2016 2:49 pm

Cactusdave wrote:Thanks very much for the comments.
Carlos -- that's a beautiful clear little clip illustrating the behaviour of the cirrus. It looks as though it moves from a joint in the base rather than bending when hit by the flagellate.

I have a short clip showing Euplotes daidaleos capturing and ingesting a small flagellate. The quality isn't brilliant, but at the beginning of the clip, the flagellate can be seen attempting to escape from the buccal cavity at the upper left of the Euplotes. At 00.13 min. it is sucked into the cytostome and disappears into a food vacuole.

https://vimeo.com/154061917

Excellent video!

75RR · Post by **75RR** » Wed Feb 03, 2016 9:18 pm

Very nice videos.

Technical question: Are you using the 40x/0.95 Planapochromat with the Plan 40x/0.65 slider?

Cactusdave · Post by **Cactusdave** » Thu Feb 04, 2016 2:18 am

Thanks Carlos and 75RR.

Yes I'm using the Zeiss X40, 0.95 dry Planapochromat with the slider intended for the X40, 0.65 Planachromat. It works well, but needs careful setting up to get the best DIC. See my earlier comment:

I have two sliders, one nominally for the X16 Zeiss Planachromat, and one nominally for the X40 Planachromat. I have a Zeiss DIC condenser with prisms I, II and III, phase rings Ph1 and Ph2 and brightfield. For this video I used a Zeiss X40, 0.95 dry Planapochromat mounted in the X40 slider in place of the X40 Planachromat. I find this combination works well, giving DIC with both the II and III condenser prisms. The II probably works best. Good DIC effects need careful optimisation of all the centring options for the condenser itself (careful setup of illumination), and the condenser DIC prisms (same controls as for centring the phase rings) and of the rotating control knob on the slider itself. With care very good results can be obtained with this lens e.g. http://www.photomacrography.net/forum/v ... 468#182468

http://www.photomacrography.net/forum/v ... 430#183430

zzffnn · Post by **zzffnn** » Thu Feb 04, 2016 6:14 am

Thank you, Dave. Your video is beautiful!

If you close down condenser diaphragm slightly, would you be able to get the entire Euplotes in focus for your 40x 0.95? I understand you may prefer to maximize resolution though. And I assume your 40x 0.95 is the DIN version (not short Jena on extender)?

Cactusdave · Post by **Cactusdave** » Thu Feb 04, 2016 10:43 am

Thanks zzffnn. Good DIC needs careful attention to setting Kohler illumination to start with. Once I've optimised the condenser (aperture) diaphragm for this I don't touch it. The field diaphragm can be closed a little to improve contrast, but it's not very helpful in controlling depth of focus at this magnification. Yes the 40X 0.95 is the Zeiss West Planapochromat, not the short non-DIN length 40X 0.95 apochromat sold by Lomo and Zeiss Jena, which though a good lens, is a much older design.

RogelioMoreno · Post by **RogelioMoreno** » Sat Feb 06, 2016 6:15 am

Very nice videos!

Rogelio

Protos · Post by **Protos** » Sat Feb 06, 2016 10:51 am

Great job !

Phil

tsavorite · Post by **tsavorite** » Sat Feb 06, 2016 11:34 am

Both wonderful videos. I especially like the first one.

Cactusdave · Post by **Cactusdave** » Sun Feb 07, 2016 10:35 am

Thanks Phil, Rogelio and tsavorite.