MicrobeHunter.com Microscopy Forum

The small flagellate Bicosoeca (Bicoeca) lives in a clear lorica and extends a long flagellum to bring in food. Large numbers of these organisms can often be found together attached to a filament of algae or another substrate. Attached to the end of the Bicosoeca cell body and the bottom of the lorica is a contractile fiber which allows the Bicosoeca to retract into its lorica when disturbed. You can see this in the photo. I am also attaching a video showing a couple of Bicosoeca in action. At the end of the video, you can see two Bicosoeca contract, pull in their flagella and then unfurl them into the medium to resume feeding.

Photo and video were taken using a Canon 1300D camera attached to a Zeiss Photomicroscope III. Objective was 40x plan achromat, optovar set at 2x (DIC) and flash.