Anabaena have a very distinct life history compared to many of the other forms of blue-green algae.  First, they are colonial organisms.  Image courtesy of Micheal Shaw.The long chains of Anabaena cells are known as trichomes.  These trichomes consist of long unbranched chains of vegetative cells, with heterocysts and akinetes spaced throughout the chain. 

While Anabaena is an algae, it is slightly motile through a gliding type movement, which is also a way to separate it from a close relative, Nostoc. It is thought that this movement is caused by waves of propulsion across the entire trichome!  Also, it is believed that a slime secretion is used to aid in movement.                    Image courtesy of UW-Madison Botany and Mike Clayton    


Anabaena typically reproduce via fragmentation.  Fragmentation is where a section of the chain will split off and either float or glide away.  After a while these sections begin to form their own chains.  These sections are known as hormogonia, and arise via the separation of adjacent cell walls.  They are also caused by dead cells that become separation discs.

Image taken by Dr. Greg Sandland.Anabaena is not just a free living organism, it also has many symbiotic relationships with other organisms! To learn more about these relationships, lets head over to the interactions page.

You can also look at other aspects of Anabaena by going back to the home page.