Chapter VI-Appendix I. Cyanobacteria identification 1

The face of evil is always the face of total need
William S. Burroughs

After posting Chapter VI it occurred to me to take a sample of my cyano into work, have a look at it under the microscope and take some photos. It's a light microscope, so I couldn't see enough detail to know what species it was. But I could see enough to take a stab at which genus of cyano I had.  A genus is a group of species that all share some common characteristics. I found a website called phycokey (amazing website based at the University of New Hampshire) that helps you identify which genus of cyano you're dealing with based on some pretty obvious features. Here is the link.

This is a low mag view and as you can see my cyano is filamentous (chains of cells not single cells). The filaments are not branched.

This is x400 magnification. You can see that the bluey green pigment isn't confined to sub-compartments of the cells like it would be in an algae (algae can grow in chains as well). That's a good start, I don't have to re-name this blog. The next question you have to answer on phycokey is 'are the filaments tapered?'. From these photos you'd have to say most are not, but maybe I have a mixed cyano population because that filament coming in from right-field is definitely tapered. Anyway, next question is 'do the filaments have heterocysts?'. Heterocysts are specialized cells that enable cyano to fix inorganic nitrogen from the atmosphere. I looked at a load of photos of filamentous cyanobacteria that have heterocysts, and the heterocysts always looked different from the other cells in the chain. These cells all look the same so I'm saying no. Next question is 'do the filaments have a sheath?'. For some cyano that have sheaths, multiple filaments are contained within the sheath and the photos of cyanos where single filaments had sheaves looked nothing like these so I'm saying no. That leaves two possibilities, a group of species where the filaments form spirals or Oscillatoria.

This is a photo from the web of Oscillatoria posted by Paul G. Davison Professor of Biology at The University of North Alabama. I see some of the filament ends are tapered as well. Well i'm pretty happy to call my cyano an unknown species from the genus Oscillatoria. But what does that tell me? In Appendix II I'll post what I have discovered about Oscillatoria species.