This was collected from the intertidal zone at the Mediterranean

It is an homocystous cyanobacteria with straight trichomes. A thin sheath is visible.

Now , the questions: it is not motile, a little motile or very motile ?

if motile it is with or without rotation ?.

Does it produces hormogonia ?

Then I try to answer !!!

Best regards

This alga is clearly a member of the Oscillatoriales and a member of the genus Lyngbya – characterized by a single, cylindrical trichome within a single clearly defined sheath that may be colored or colorless. Not shown but likely, the sheath of this taxon will generally extend some distance beyond the trichome’s terminal cell. This photograph appears show a trichome that’s on the verge of breaking apart into small hormogone segments. In nature Lyngbya trichomes can be found entangled in mass discoloring the soil and beach sands and otherwise epilithic. I believe the trichome in this photograph may have been epilithic prior to its detachment into the water column. Other forms with a similar morphology are free floating among the phytoplankton, as Planktolynbgya.

I suggest you have a look at the section on cyanobacteria of my my personal site

(unfortunately the site is in French but I guess you can manage !)

http://www.pierre-armand-roger.fr/cyanobacteries/index.htm

The taxonomic key for homocystous cyanobacteria is on page

http://www.pierre-armand-roger.fr/cyanobacteries/pages/Taxonomie/ss3.htm

you will find some pictures of Lyngbia for comparison with your strain on page

http://www.pierre-armand-roger.fr/cyanobacteries/pages/Taxonomie/Lyngbia.htm

Best regards

Thank you both Pierre and George

Pierre I find your site very useful

As I said before the diametric feature of this species is 3 microns (No mistake)

microscopic magnification is X1000, so it might be Planktolyngbya

It was collected as colony from intertidal rock

Dear Razy:

I am not a specialist in Cyanobacterias, however I have two commets: 1) If you found the species in intertidal rocks why do you think that it belong to the genus Planktolyngbya? In Algaebase the description of this genus probably pertaining to Anagnostidis, K. & Komárek, J. (1988) says "Planktonic species, usually in large, mesotrophic reservoirs; several species limited to tropical and warm temperate zones, several species presumably nordic". 2) Aditionally the description mentions "Reproduction by fragmentation of trichomes without necridic cells into nonmotile (?) hormogonia." and I think that your picture shows necridic cells. Regards.

Dear Eugenia

I am just starting my way in Cyanobacteria taxonomy so I look for the experts help.

Thanks

Dear Razy

We all started once and it is good to ask for help. What I wanted to say is that when you think your material is a given taxon would be important to carefully look at the protologue, or at a good description to see how this is consistent with the material you are watching. The overall look and morphometric parameters are not sufficient to make reliable determinations. Succeed in the study of the Cyanophyta. Kind regards.

The reference book for procaryotes taxonomy is the Bergey's manual. I recently found that the chapter on cyanobacteria is available on the web, unfortunately without drawings. To see the drawings you have obviously to buy the book (very expensive !!)

Anyway the keys available on the web are very helpful.

Just type "bergey's cyanobacteria" in your navigator.

Thank you Pierre

I found the link

I think that i might buy this book (120$)

Cheers