Identification
The following examples are of the most common protozoa in the Sarracenia purpurea inquiline community. Many of these can be grown in monocultures and maintained in the lab. Note that the photos were taken from samples from Switzerland. The same protozoa species are the most common in North American samples.
Flagellates
Bodo sp.
Bodo sp. is one of the most common flagellates that you will see in Sarracenia purpurea inquiline samples. They are less than 15 um in size and have two flagella (one on the posterior side and one on the anterior side). The posterior flagellum is long, while the anterior flagellum is curved. It is not always possible to see the flagella with the microscope, but the best characteristic to identify microscope samples is its movement. Due to the location of the two flagella, Bodo sp. has a wiggle movement.
There is another species of Bodo that is Bodo saltans (no photo is available). The way to distinguish between the two Bodo species is that Bodo saltans is more kidney-shaped, and it has its two flagella on the top of its body (the second flagella can be difficult to see). Its characteristic movement is to attach itself to a substrate and do a flicking (or popcorn popping) movement.
Bodo caudatus (?) "gnome hat"
Another species of Bodo is what we lovingly refer to as the "gnome hat" (possibly the species Bodo caudatus). It has a a slightly fatter bottom than Bodo sp. and can be larger in size.
Chrysonomad sp.
Chrysomonad sp. (Poterioochromonas/Ochromonas) is the second type of common flagellate in S. purpurea samples. It is round in shape with a distinct flagella. It moves slower than species of Bodo and has a bit of a looping movement, as if it is a ping pong stuck in a current of air.
Note that yeast is also present in S. purpurea samples, which will also be round in shape, but they will not be moving.
Ciliates
Tetrahymena sp.
Tetrahymena sp. is less than 50 um in size. It does not have any real distinct features except that it is elongated oval shape.
Colpidium sp. (photo source)
Colpidium sp. can easily be confused with Tetrahymena because they can roughly be the same shape and size (40-100 um). Two distinct features of Colpidium sp. is that it has a characteristic notch/mouth that is missing from Tetrahymena and the vacuoles are distinguishable inside Colpidium.
Colpoda sp.
To add to the confusion is Colpoda sp.. This ciliate is smaller than Colpidium and has a rounder, more kidney-shape than Colpidium.
Colpoda steinii
Colpoda steinii is much easier to determine because of its very distinct groove and kidney shape. This protozoa can also become quite large compared to the other common ciliate species.
Cyclidium sp.
Cyclidium sp. is an extremely fast ciliate that is smaller in size (30 um) than the other common ciliates. The best way to identify this species is by the speed at which it moves...which is fast! It will suddenly stop its movement, and it is only then that you can see its very distinguishable long cilia all around its body, with one long cilium in the back (the caudal cilium, which is difficult to see in this photo).
Other members of the microscopic world of S. purpurea inquilines
Euglena sp.
Euglena sp. is a photosynthetic flagellate that will be green when there is light available. It can have the long, rigid look as in the photo, but is also malleable in shape formation and can shift into smaller and fatter shapes.
In terms of other photosynthetic organisms, you will also find algae in the samples.
Bdelloid rotifer
In North America, the most common rotifer will be the bdelloid rotifer, Habrotrocha rosa. The rotifer in the photo is actually the bdelloid rotifer that is found in Sarracenia purpurea leaves in Switzerland. It's movements are similar to that of its North American counterpart, but it is a different species.
Mite
In North America, the mite inhabitant of S. purpurea leaves is Sarraceniopus gibsoni. There is also a mite present in the leaves in Europe (photo from samples in Switzerland). It actually might be the same species as that in North America, according to new research published by SPIN members: Goddard EL, Naczi R, Walker K, Millett J, Wood PJ (2022) First records of the pitcher plant mite Sarraceniopus gibsoni (Nesbitt, 1954) (Astigmata: Histiostomatidae) in Europe. BioInvasions Records 11(1): 62–69
Nematode
Non-segmented, with whip-like movements.
Ciliate cell division + lots of bacteria
Two common things that will be seen with the microscope are 1) ciliate protozoa cell division, 2) many moving black spots in the background. Those are the bacteria!