Not sure on these specimens

[D0c]

Found these today.

Any help would be appreciated. I'm thinking Nassula or maybe Frontonia atra

Video 1 & 2 show the same critter. Video 3 shows another critter but in the same sample as the other one.

Video 1 - https://www.flickr.com/photos/154534235 ... ateposted/
Video 2 - https://www.flickr.com/photos/154534235 ... ateposted/
Video 3 - https://www.flickr.com/photos/154534235 ... ateposted/

[Bruce Taylor]

Frontonia would be flattened, and this guy is very round, so we can rule that out (Frontonia don't rotate as they swim). Nassula species don't move like this, typically, and should have an oral basket, and compact macronucleus. This critter's macronucleus seems to be long, so it could be a species of Ophryoglena. However, it could also be a prostomatean (e.g. Prorodon). The problem is, we can't see where the mouth is located. Without seeing the mouth, it's very hard to be sure about this. So: it's a ciliate.

[D0c]

Thanks for trying Bruce.