While covering protists in Principles of Biology II this week, the samples I projected to the class were quite exciting, so I created a few quick videos. And it’s been ages since I’ve shared anything on here… so, here’s a video of an engulfed Paramecium inside of an Chaos amoeba (badass genus, but not quite as cool as the yabby, Cherax descructor).
The amoeba is actively crawling around with pseudopods, and there are some other contaminate ciliates, including other Paramecium. Additionally, there are rotifers buzzing around and attaching themselves to the amoeba’s membrane, occasionally succumbing to the voracious predator. But, and this always blows my mind, rotifers are animals, composed of at least 1000 cells, while the amoeba is a single cell (although one of the largest)—look at the difference in scale!
The second video was also surprising. Normally, Pediastrum doesn’t pose much of a problem for students to find, since it’s relatively large and the colonies are abundant and sessile, not to mention bright green. This semester, there were some struggles across multiple section of the course, possibly because the algae weren’t doing well in their vial. So, I projected it only to find small moving swiggles bombarding the Pediastrum. My first thought were motile gametes or spores, but a colleague pointed out that their gametes and spores are more-or-less spherical…and these are spiral-like. My next thought—Sprillium bacteria! HUGE!