Swirling Tail: SEM of a Dinoflagellate

The "Montauk Monster" is a little nasty looking. This SEM photograph is much nicer.

dinoflagellate, originally uploaded by sconartist.

I showed this image to introductory biology students, and some were able to identify the single-celled algae right away. The give away is the spiral-like flagellum resting in the central groove. (If you don't know what a flagellum is you can think of it as a tail that propels a single cell.)

The spiral-like tail causes the cell to spin as it moves through the water - thus it's name. "Dino" means spinning, and "flagellate" refers to the cell's tail.

The Smiling Parasite: Giardia lamblia

When I first showed my brother this picture of an axolotl he said, "Go away. That doesn't exist." (Too cute.)

What a great reaction! So when I received a similar reaction to Giardia lamblia this evening I knew it was time to blog.


See more images of giardia. (The scientific diagrams are especially cute looking.)


Giardia lamblia is a single celled organism. What we perceive as eyes are actually twin nuclei (spherical compartments that contain DNA) and the "mouth" is a parabasal body (don't ask).


This notably cute protozoan is responsible for giardiasis (better known as beaver fever and backpacker's diarrhea) and symptoms include "loss of appetite, lethargy, fever, explosive diarrhea, hematuria (blood in urine), loose or watery stool, stomach cramps, upset stomach, projectile vomiting (uncommon), bloating, flatulence, and burping (often sulphurous)." [Wikipedia] Giardia lamblia lives in the small intestine and spreads when infected fecal particles are able to contact food or water that will be ingested.

Despite appearances, giardia is quite nasty.

• Giardia lamblia artwork on flickr
• Giardia lamblia Giant Microbes plushie