The notoriously difficult task of identifying hypotrichs to genus level

[rhiannontries]

I have some footage of a hypotrich:

https://m.youtube.com/watch?v=aYZ2EfsBIsI

(Crappy YouTube quality will be the end of me)

I think I can just make out a midventral complex, which I believe would put this ciliate with the urostyloids. I do not have enough knowledge on hypotrichs to go much further. Foissner and Berger’s “User-friendly Guide to the Ciliates” does not seem to be very extensive in the hypotrich category, and does not include many species that I have seen elsewhere. According to it, I think this ciliate is in the genus Holosticha? But I am not quite convinced. Anyways, thoughts?

[smollerthings]

I think you can get better youtube quality if you rotate 90 degrees? Also nice touch on the horror movie sound at 1:50

[rhiannontries]

Thanks for the tip! Haha, I think a car passed by my window

[Bruce Taylor]

I watched to the end but didn't see a midventral complex (it might help to let me know what time it appears). The long flexible body is certain typical of urostyloids, but similar bodies occur in oxytrichids, amphisiellids, etc.

If this is a freshwater sample, we can rule out Holosticha. Following a revision of the urostyloids in 2005, there is only a single freshwater species of Holosticha left, H. pullaster (a very easily-identified ciliate, with its CV in the posterior third of the cell). Most traditional species of Holosticha are currently in Anteholosticha.

In my opinion, we don't see the somatic cirri clearly enough for an identification below subclass Hypotrichia.

[rhiannontries]

Thanks for trying Bruce! Good to know about Holosticha, thank you. Going forward, I’ll be sure to find ways to improve video quality.