Many green algae move using flagella, hair-like structures that beat rhythmically, propelling the cell through the water. Think of it like a tiny breaststroke swimmer! This whip-like motion is similar to the cilia found in the human respiratory system. Some species possess two flagella, working in coordination to achieve efficient movement. For example, the green alga Chlamydomonas, found abundantly in freshwater ponds, uses this method of locomotion. [1, 2, 10]
The movement isn't always about swimming. Certain types of green algae, such as filamentous algae, can also exhibit movement as bundles, described as "moving freely like a tumble."[7] This is less a directed movement and more a passive shifting due to water currents and other environmental factors.
While some algae, like Chlamydomonas, are actively motile using flagella, the movement of algal blooms themselves is primarily influenced by water currents and tides. Blooms can spread and shift location within a water body due to these forces, even though individual algae cells may possess flagella for independent movement. [3, 5] Therefore, the movement of a large collection of algae is quite different from the motion of a single cell.
Types of Green Algae Movement Summarized:
- Flagellar Movement: Active, directed swimming using whip-like flagella. This is typical of many single-celled green algae.
- Passive Movement: Movement through water currents and tides, observed in large algal blooms or entangled filamentous algae.
