Aidan Fenix, a graduate student at Vanderbilt University, captured this image in the MBL's Physiology course, where he is a student this summer:

The image shows the largest known extant unicellular organism, called a Stentor, and emphasizes the animal's cilia. The “hairy” cilia on the left are used to help the animal swim, while the ones one the right that almost resemble a toothbrush are for filter-feeding — trapping and ingesting algae. The cilia are constructed by microtubules, structures made of a fibrous protein. Fenix captured the image with a Zeiss laser-scanning confocal microscope, and used image analysis software to color-code how close the cilia are to the Stentor cell structure. The “bottom” cilia, those closest to the cell, are in red, while green and blue are near the “top," and nearer to the microscope's lens.

“What I love most about this kind of image is it’s beautiful, but it can tell you something as well — it shows you the structure of the animal in amazing detail,” says Fenix.