Cyclidium

carlos.uruguay · Post by **carlos.uruguay** » Mon Nov 09, 2015 5:42 pm

We have already filmed before this little ciliated of about 20 um (0.02mm) long.
We found it in a pond in front of a house in Montevideo - Uruguay - South America.
It has a long cilia in its rear end and an undulating membrane reaching half of its body.
100X immersion objective
Phase contrast.
Panasonic GH4 camera.
Video link:
https://www.youtube.com/watch?v=ZvZYdoW7GXs
Video frame preview:

Regards
carlos

Sumguy01 · Post by **Sumguy01** » Mon Nov 09, 2015 8:20 pm

Very interesting.
Thanks for sharing.

zzffnn · Post by **zzffnn** » Mon Nov 09, 2015 9:25 pm

Great job Carlos!

How did the ciliate look under oblique+Pol? Not as contrasty as phase? Did you prefer phase because it showed the undulating membrane better?

What is that white spot inside the ciliate? Macronucleus? Your phase contrast seems to highlight that a bit. Did that white spot show up well in oblique+Pol?

Thank you!

Jacek · Post by **Jacek** » Tue Nov 10, 2015 3:44 am

SUPER !

carlos.uruguay · Post by **carlos.uruguay** » Tue Nov 10, 2015 5:01 am

Thank you Sumguy01, Jacek and Fan for your kind comments

zzffnn wrote:How did the ciliate look under oblique+Pol?

http://www.photomacrography.net/forum/v ... =cyclidium

zzffnn wrote:What is that white spot inside the ciliate? Macronucleus?

It has 3 membranelles placed to the left side and an undulating membrane on the right side.
Inside it has numerous digestive vacuoles. A one contractile vacuole, in the posterior third. The nucleus is located in the anterior third of the citosoma

zzffnn wrote:Your phase contrast seems to highlight that a bit. Did that white spot show up well in oblique+Pol?

I like the phase contrast

Bruce Taylor · Post by **Bruce Taylor** » Tue Nov 10, 2015 6:11 am

Superb phase contrast! Cyclidium heptatrichum is a reasonable guess, given the size and lack of cilia in the middle of the body...but, in truth, the cyclidiidae (Cyclidium, Cristigera, Apocyclidium etc.) are a mess, mainly because morphological characters in the scuticociliates are very weak indicators of relatedness. All the little scutis looks kind of the same.

carlos.uruguay · Post by **carlos.uruguay** » Tue Nov 10, 2015 6:37 am

Bruce Taylor wrote:Superb phase contrast! Cyclidium heptatrichum is a reasonable guess, given the size and lack of cilia in the middle of the body...but, in truth, the cyclidiidae (Cyclidium, Cristigera, Apocyclidium etc.) are a mess, mainly because morphological characters in the scuticociliates are very weak indicators of relatedness. All the little scutis looks kind of the same.

Thanks Bruce. Considering that it is freshwater and a small size, which title suggesting that puts to the video?
"probably Cyclidium"?
Regards!

carlos.uruguay · Post by **carlos.uruguay** » Tue Nov 10, 2015 6:44 am

Bruce Taylor wrote:Superb phase contrast! Cyclidium heptatrichum is a reasonable guess, given the size and lack of cilia in the middle of the body...but, in truth, the cyclidiidae (Cyclidium, Cristigera, Apocyclidium etc.) are a mess, mainly because morphological characters in the scuticociliates are very weak indicators of relatedness. All the little scutis looks kind of the same.

Bruce, the long terminal cilium with bent and thinner end, is present in all similar genres?
Regards

RogelioMoreno · Post by **RogelioMoreno** » Tue Nov 10, 2015 7:48 am

Carlos,

Very nice pc video!

Rogelio

Bruce Taylor · Post by **Bruce Taylor** » Tue Nov 10, 2015 8:37 am

carlos.uruguay wrote:Bruce, the long terminal cilium with bent and thinner end, is present in all similar genres?
Regards

The long caudal cilium is found in most scuticociliates. I don't recall having seen that hooked end mentioned as a taxonomic character, but my memory might be faulty.

I think Cyclidium is a reasonable identification (probably C. heptatrichum). The genus is very poorly defined, and polyphyletic as well, with species in both Cycilidiidae and Thigmotrichidae, so there's not much risk of misleading anyone.

carlos.uruguay · Post by **carlos.uruguay** » Tue Nov 10, 2015 8:44 am

Thanks Rogelio

carlos.uruguay · Post by **carlos.uruguay** » Tue Nov 10, 2015 8:45 am

Bruce Taylor wrote:
carlos.uruguay wrote:Bruce, the long terminal cilium with bent and thinner end, is present in all similar genres?
Regards
The long caudal cilium is found in most scuticociliates. I don't recall having seen that hooked end mentioned as a taxonomic character, but my memory might be faulty.

I think Cyclidium is a reasonable identification (probably C. heptatrichum). The genus is very poorly defined, and polyphyletic as well, with species in both Cycilidiidae and Thigmotrichidae, so there's not much risk of misleading anyone.

Thanks Bruce!
Anyway I Will put "Probable Cyclidium"

zzffnn · Post by **zzffnn** » Tue Nov 10, 2015 11:54 am

I wanted to know what those bright spots inside the ciliates are, so I read carefully about phase contrast, ciliate anatomy and also asked our expert - Bruce.

The following is a private message that I sent to Bruce. He agrees with my 2nd guess that those bright spots might be food vacuoles (my 1st guess, macronucleus, was probably wrong since it should be darker in positive phase contrast). Bruce also added that macronucleus may be difficult to see in well-fed ciliates.

Start quoting my message to Bruce:

I read about phase contrast carefully and actually think that bright spot may be food vacuole. I think Carlos is using dark (positive) phase, so macronucleus should have darker color than other structures as it has higher refractive index - it should not appear that bright.

Food vacuole has mostly water, so its color would be pale in positive phase contrast, like what we saw. Also, if you look at Carlos' video more carefully, those ciliates do seem to have pale color contratile vacuole (CV) at the end of their bodies (and you can see them contracting). The CV's color is similar to that big bright spot, which suggests that the bright spot contains water - thus food vacuole (FV) seems more likely. Also, some bright spots seem to have dark inner contents, which would make sense if those are food vacuoles containing water and denser food particles?

Carlos showed us brightfield (oblique+pol) video of the same type of ciliate: https://www.youtube.com/watch?v=_jKu3jqUqJE
I saw similar looking CV and FV in phase and brightfield. In brightfield, I saw some empty-looking vacuoles (food vacuoles) that seem to correlate to size and position of those bright spots.

End of quoted message.

Edit: I still consider my guess of food/digestive vacuoles a guess though. This is because in phase contrast, color is related to light path difference (LPD) and LPD = thickness x refractive index. Since we are not sure about thickness and thickness can be so different that it can change colors/LPD around, I would still call it a guess.

carlos.uruguay · Post by **carlos.uruguay** » Tue Nov 10, 2015 12:18 pm

Very interesting Fan! (zzffnn)

piermicro · Post by **piermicro** » Mon Nov 16, 2015 1:02 pm