Convinced of a link between GFO and Cyano (and not the good kind)

[asylumdown]

Originally Posted by Myka

I'm curious how you have come to the conclusion that the cyano in our tank is likely Oscillatoria? Is that your own ID from your microscope or are you reading this in your research?

oops, missed that. What I get for typing on an iPhone all day. I was curious about it because there's so many species out there so I started looking in to cyano taxonomy. The Smithsonian Tropical Research Center maintains a great site with pictures of different cyano species in the wild, and Berkley also maintains a pretty good (if unsophisticated) site on cyanobacteria as well. The different genera are pretty distinctive in their behaviour, morphology, and appearance. Oscillatoria is the only genus that fits the bill as a group. It's the only one that forms mats of slimy 'cyano' like substrate coating goos in tropical marine environments. You can look at a bunch of pictures here: http://biogeodb.stri.si.edu/pacifica...lue/flocculent

Going beyond genus to species would take a microscope way better than mine, and even people who are experts on this as a career never seem to agree. This is what it looks like under my super crappy microscope (it's a video so you need to click on it):



That magnification wasn't high enough to see the heterotrophic and chemoautotrophic bacteria that live in association with the cyano mat, but you can see the super cool stretched out diamond shaped diatoms and a couple of the watermelon seed shaped dinoflagellates that live in association with the film. It's called "Oscillatoria" because the filaments re-orient themselves by oscillating back and forth until they are positioned as best as possible to receive the light, which is why the strands look like they're vibrating. I think it might be part of why cyano mats seem to shrink at night, the entire colony can deflate at night, then puff up over the course of the day as individual filaments stretch out to try and get the most light.