The attached photo is of a cryptomonad. Cryptomonads, along with the Chlororachniophytes, are the only organisms known to possess organelles (cell parts) called nucleomorphs. The function of nucleomorphs has not yet been clearly defined, but they are similar to the primary nucleus (“cell brain” or “cell headquarters”) of the cell. Nucleomorphs are enclosed with chloroplasts (organelles which carry out photosynthesis) by means of a series of membranes. Cryptomonads are an example of flagellates not in Excavata. For more on those two terms, visit the About page.
This photomicrograph was taken at a relatively low magnification (the actual number escapes my memory). In the photo, you can see one of the large, ciliated protists swimming out in the open and another foraging in some detritus.
Rotifers are microscopic animals in the phylum Rotifera. This particular specimen, of the rotifer class Bdelloidea, possessed rotating cilia around its mouth.
I use a home-made dark field filter on my microscope. Dark field microscopy is used typically to identify and locate specimens quickly, but it also makes for great photomicrographs! The attached photo is of some pond scum I found. Dark field microscopy works by illuminating only the specimen, leaving the background dark.
In one species of Vorticella that I found, the daughter cell possessed a posterior ring of cilia, with the cytostome on the other end. When the daughter Vorticella finally detatched from its predecessor, it started to swim backwards! Unfortunately, I was not able to photograph this stunning spectacle.
Vorticella is a single cell in the subclass Peritricha. Vorticella features a characteristic feeding current (or vortex, hence the name) created by cilia encompassing the mouth (cytostome), as well as a long, contractile stalk which allows the cell to contract like a spring when disturbed. I was lucky enough to find a Vorticella producing offspring, as you can see in the attached photomicrograph (a photograph of something microscopic).
Here’s the “cyclops” at a lower magnification. You can just make out the single eye towards the copepod’s anterior.
This organism was previously misidentified as a water flea…actually, it’s a copepod larva. For more on copepods, see later posts.