The first species is a colonial cyanobacterium called Gloeotrichia. It is relatively large and colonies can easily be seen as small dots on the surface of the water. During the night, they seem to sink and are no longer floating, but the reappear as soon as the sun starts to rise. I have tried to keep these alive in a water sample in my garage, but they are very difficult to culture and keep alive. I have tried various temperatures and lighting conditions, but all attempts have failed so far.
The second set of images are a microscopic colony of the green algae called "Botryococcus braunii”. It measures about 140 micrometers across. Colonies are held together by a lipid (oily) biofilm and you can see old droplets around the edge of the colony. Typically around 30–40% of the dry weight of a colony is oil. Blooms of Botryococcus braunii have been shown to be toxic to other micro-organisms and fish but they may have other applications than being a source of food. Botryococcus braunii has great potential for algaculture because of the hydrocarbons it produces, which can be chemically converted into fuels. Botryococcus oils can be used as feedstock for hydrocracking in an oil refinery to produce octane (gasoline), kerosene, and diesel.
The third species I found in large amounts are another cyanobacteria, Aphanizomenon. Here photographed in darkfield illumination.
Gloeotrichia in darkfield illumination. Olympus UplanSAPO 4X objective. Focus stacked:
Cyanobacteria - Gloeotrichia by Håkan Kvarnström, on FlickrI call this one "Dancing ballerinas". Gloeotrichia in fluorescent illumination (ultraviolet). Olympus UplanXAPO 10X objective. Focus stacked:
Cyanobacteria - Gloeotrichia by Håkan Kvarnström, on FlickrGloeotrichia in fluorescent illumination (ultraviolet). Olympus UplanXAPO 10X objective. Focus stacked:
Cyanobacteria - Gloeotrichia by Håkan Kvarnström, on FlickrGloeotrichia in fluorescent illumination (ultraviolet). Olympus UplanXAPO 40X objective. Single shoot:
Cyanobacteria - Gloeotrichia by Håkan Kvarnström, on FlickrGloeotrichia in fluorescent illumination (ultraviolet). Olympus UplanXAPO 40X objective. Single shoot:
algalblooCyanobacteria - Gloeotrichiam-4 by Håkan Kvarnström, on FlickrBotryococcus braunii in DIC. Close to crossed polarizers. Olympus UplanXAPO 60X Oil objective. Focus stacked:
Green alga - Botryococcus braunii by Håkan Kvarnström, on FlickrBotryococcus braunii in DIC. Relaxed polarizers with DIC slider slightly pulled out. Olympus UplanXAPO 60X Oil objective. Focus stacked:
Botryococcus Braunii by Håkan Kvarnström, on FlickrAphanizomenon in darkfield illumination. Olympus UplanXAPO 20X objective. Focus stacked:
Cyanobacteria - Aphanizomenon by Håkan Kvarnström, on Flickr
