Identification help - Is this Cothurnia?

billporter1456 · Post by **billporter1456** » Sat May 17, 2014 12:57 pm

I am looking for an identification of this ciliate. I believe it is a species of Cothurnia, but would like to be more sure before I upload a longer version of this video.

https://www.youtube.com/watch?v=05bdftg ... e=youtu.be

Bruce Taylor · Post by **Bruce Taylor** » Sat May 17, 2014 2:26 pm

Hi Bill. No stalk on the lorica, and no valve, so it's a species of Vaginicola.

Very nice video!

billporter1456 · Post by **billporter1456** » Sat May 17, 2014 3:27 pm

Bruce Taylor wrote:Hi Bill. No stalk on the lorica, and no valve, so it's a species of Vaginicola. Very nice video!

Thanks, Bruce! I had read that Cothurnia may or may not have a stalk on the lorica and I don't think they have a valve. Just about every image I found of Vaginicola showed two of them in the lorica and they were often full of algae, so that threw me off. I could see that it was not Thuricola because of not having a valve. I could never find a video or image that looked just like my specimen, so I threw myself on the mercy of the forum.

I want to put up a longer version of the video that includes a time-lapse of organism. I wanted to get a better handle on the identification before making the longer version. I am perfectly happy identifying it as Vaginicola, a name that borders on being XXX rated. Thanks again.

Bruce Taylor · Post by **Bruce Taylor** » Sat May 17, 2014 8:30 pm

Bill, if you are getting that from Kudo or the (useful, but unreliable) Protist Information Server (http://protist.i.hosei.ac.jp/pdb/images ... index.html) look more closely. The description "with or without stalk" applies to the family (Vaginicolidae) not the genus (Vaginicola, Cothurnia). The genus Cothurnia is explicitly "with stalk." (Curds, p. 190), or as Kudo puts it, with "lorica attached aborally by stalk." Number of organisms within a lorica is not a taxonomic character. I can send you Warren's revision of Cothurnia, if you're interested.

That said, the phylogeny remains in question. In other loricate or testate species (Tintinnids, the testate amoebae, etc.) it has turned out that the morphology of the shell/lorica/test is not necessarily a valuable character. The molecular phylogeny of the Vaginicolidae hasn't been settled, but it would not surprise me if the stalk turned out to be an irrelevant character!

In the meantime, though, "no stalk, and no valve = Vaginicola."

billporter1456 · Post by **billporter1456** » Sun May 18, 2014 1:54 pm

Bruce Taylor wrote:Bill, if you are getting that from Kudo or the (useful, but unreliable) Protist Information Server (http://protist.i.hosei.ac.jp/pdb/images ... index.html) look more closely. The description "with or without stalk" applies to the family (Vaginicolidae) not the genus (Vaginicola, Cothurnia). The genus Cothurnia is explicitly "with stalk." (Curds, p. 190), or as Kudo puts it, with "lorica attached aborally by stalk." Number of organisms within a lorica is not a taxonomic character. I can send you Warren's revision of Cothurnia, if you're interested.

That said, the phylogeny remains in question. In other loricate or testate species (Tintinnids, the testate amoebae, etc.) it has turned out that the morphology of the shell/lorica/test is not necessarily a valuable character. The molecular phylogeny of the Vaginicolidae hasn't been settled, but it would not surprise me if the stalk turned out to be an irrelevant character!

In the meantime, though, "no stalk, and no valve = Vaginicola."

Bruce, I'm guilty as charged!

I did go to the Protist Information Server and I do have Kudo's book. Actually, had I checked Kudo, I would have been more likely to get the right genus. Anyway, here's the extended version of the video with a nice little time-lapse sequence.

https://www.youtube.com/watch?v=k9eXyt9QiY4