While looking through the samples taken from the bird bath I came across this little critter. I have attached three videos the first looks like a Trachelius but on closer inspection and looking at the other two videos I think it's a Acineria sp maybe a incurvata. I say this because you can see a posterior CV, two nuclei, rows of cilia along the right hand side of the neck.
What do you think?
https://www.flickr.com/photos/154534235 ... ateposted/
https://www.flickr.com/photos/154534235 ... ateposted/
https://www.flickr.com/photos/154534235 ... ateposted/
Acineria sp
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Bruce Taylor
- Posts: 1002
- Joined: Fri Sep 04, 2015 11:34 am
Re: Acineria sp
I think you have three different organisms here. The first one does resemble Trachelius, as you note. However, it lacks that ciliate's clear cytoplasm filled with large vacuoles, and Trachelius has only a single macronucleus (while the similar genus Apotrachelius has a scattering of small nodules). The 2 macronuclei and posterior vacuole are features common to many ciliates in the order Pleurostomatida. Your creature could be a stout Acineria incurvata (in their revision of the genus Foissner and Augustin record a "Trachelius-like form" that is quite similar to what we see here). However, it might also be a chubby Amphileptus of some sort, such as A. punctatus, A. wilberti or A. piger (that last species is a good candidate for the critter Ehrenberg called "Trachelius anaticula"). I think identification would require a closer view of the cell, particularly the oral structures and associated extrusomes.
The second one is certainly in Pleurostomatida, but looks more like Litonotus than Acineria. That long proboscis appears to be lined with extrusomes (toxicysts), and it is likely that the mouth runs in a slit about a third of the way down the cell (and not just on the anterior edge, as in Acineria).
The last one appears to be Lacrymaria! The mouth is a slightly darker spot at the tip of that narrow neck (which resembles a hose, and is not flattened and asymmetrical, as it would be in a pleurostomatid). At a few points the cell contracts and we catch a glimpse of spiral ciliary rows, which is a very strong clue. The creature is not stretching its neck to outrageous lengths, in the classic style of Lacrymaria olor, probably because it is swimming rather than feeding...though it is also possible that the specimen is immature (a recent divider), or is in the process of regenerating its proboscis.
The second one is certainly in Pleurostomatida, but looks more like Litonotus than Acineria. That long proboscis appears to be lined with extrusomes (toxicysts), and it is likely that the mouth runs in a slit about a third of the way down the cell (and not just on the anterior edge, as in Acineria).
The last one appears to be Lacrymaria! The mouth is a slightly darker spot at the tip of that narrow neck (which resembles a hose, and is not flattened and asymmetrical, as it would be in a pleurostomatid). At a few points the cell contracts and we catch a glimpse of spiral ciliary rows, which is a very strong clue. The creature is not stretching its neck to outrageous lengths, in the classic style of Lacrymaria olor, probably because it is swimming rather than feeding...though it is also possible that the specimen is immature (a recent divider), or is in the process of regenerating its proboscis.
Re: Acineria sp
Great stuff
Gives me a lot of info to google and read up on.
Thanks for your help again.
Gives me a lot of info to google and read up on.
Thanks for your help again.
Leitz SM-Lux