Some type of loricated peritrich?

[Free2Fish]

Found this little fellow in a jar I was trying to get bacterial growth with some rice grains. It was swimming around until it got stuck in some fibers. The body is 36 um long, the stalk 30 um long and 3.6 um wide. Looks like some type of loricated peritrich.

[Bruce Taylor]

It is a peritrich, but not a loricate one (it has no lorica! ). It is in the order Sessilida, and the poor thing is in some distress. Identification of sessilids usually begins with examination of the stalk, but in this case the organism has been uprooted, and we have no way of knowing what its normal adult feeding form would be. So, identification below order would be only a guess.

[Free2Fish]

Thanks Bruce. At one point when it was still swimming it had withdrawn its “head” so I assumed it was into a lorica. Much to learn.
So is the structure here in Codonella cratera considered a lorica?

[Bruce Taylor]

So is the structure here in Codonella cratera considered a lorica?

Yes, the vaselike structure in which Codonella cratera lives is called a lorica (it's not a peritrich, though, but a tintinnid).

It is possible that the "stalk" in the first image is just a bit of adhering debris, in which case it might indeed be a loricate ciliate of some kind. Do you have more images, or video?

[Free2Fish]

Is there a difference between a lorica and a test?

I have a video but it only showed the organism after it got stuck. I couldn’t get any photos at 40X before I got stuck because it was moving too fast. I’ll upload it to YouTube later today.

Harry

[Bruce Taylor]

Is there a difference between a lorica and a test?

The word "test" is only applied to the shells of amoeboid organisms. It's an awkward term, and the trend in recent years has been toward using the word "shell" instead. In ciliates, any protective structure is usually referred to as a "lorica", though the term "case" is sometimes used. Composition of loricae varies quite a bit. Some are just loose gelatinous tubes, others incorporate found particles or are formed into sleek, transparent vases or bottles.

[Free2Fish]

As a layperson trying to read Biological papers I find I have to learn an entirely new language to even begin to understand them. I've downloaded a number of glossarys but none of them are close to complete. Is there a 1000 page tome out there that I've missed?



I think I've solved the mystery. I went back to the jar and found a number of single peritrichs that are of similar size. You were right, it's a very distressed peritrich with a broken stalk and myoneme. Here is another specimen that is intact with similar dimensions.





Thanks, Harry