Many single celled eukaryotes do the same things animals do--feed themselves, evade predators, and reproduce--but do it all with only a single cell. Like animals, protists display both huge variations in "body plans" as well as complex behaviors. Here are a few of our favorites, from our lab and elsewhere.
At the Molecular Evolution and the Cell SMBE Satellite Meeting a few weeks back, one of the organizers Nels Elde showed me this video he took of Lacrymaria feeding on other ciliates. He says: "Lots of folks assume that Lacrymaria's probing behavior represents feeding, but it’s not until it successfully engulfs a prey ciliate like Tetrahymena that the feast begins through some crazy process of phagocytosis. After a meal, Lacrymaria has to reload its dense core granule arsenal to the tip of the neck before it can feed again."
This beauty, also captured by Jeremy Pickett-Heaps, caught my attention as an Honorable Mention in the 2009 Olympus BioScapes International Digital Imaging Competition.
Jeremy Pickett-Heaps knocks it out of the park with this series of videos featuring euglenoid flagellates.
If you haven't seen John Bonner's Dictyostelium movies, you're missing out! Here is a short collection from Princeton University highlighting some of the charismatic footage Dr. Bonner filmed of the collective behavior of Dictyostelium amoebae. Studies on this protist have helped us begin to understand how the dynamics of actin polymer networks gives rise to crawling behavior, and raise interesting questions about whether single celled organisms can be altruistic.
Georgia Squyres recently posted a beautiful series of movies taken as part of the Microbial Diversity course at the Marine Biology Lab at Woods Hole this past summer. Be sure to check out the rest of the series!
From the above link "Movies taken at http://www.mbl.edu/microbialdiversity/ of protist symbionts that live in the termite gut. Protists like these help termites digest the wood they eat. Termites from the Leadbetter lab, imaged in DIC. Playback speed is close to real time; scale bar = 5 µm."