The way an alga moves—or doesn’t move—is the second key characteristic used to classify groups of algae. Some algae, such as Spirogyra, are filamentous and can appear as slimy green mats on the surface of water. Other algae, like Bacillaria, use mucilage as a means to move along a surface or slide along each other. Chlamydomonas is an example of an algae that has flagella, which allows them to swim in a controlled way through their environment. Flagella can vary in complexity, number, and arrangement on an alga. Certain algae which lack flagella, can still control their position in the water column by using air bubbles inside them to regulate their buoyancy.
Andrea Halling
PhD student
Evolutionary Biology