Another picture

This species covered some rocks at the intertidal zone in Israel

I think the genus is Oscillatoria!

It seems Oscillatoria, but the shape is more changable.

Could be Oscillatoria or member of LPP group (Lyngbya, Phormidium, Plectonema)

Check sheath and cell width with key...

I'd think more likely Lyngbya, because of the rounded ends and squat/wide cells shape

you should contact Prof. Shmuel Carmeli from the Tel Aviv university he could help you with the picture. IN order to know better you should do 16s rRNA identification to know more about the genus.

I agree Jill that it is very likely a Lygnbya- sheath and cell width will help figure out...

It should be Oscillatoria or Lyngbya. The best way for the identification is 16s rRNA analyse.

Taka a look Komarek, 1992: http://www.cyanodb.cz/db/Oscillatoria/Oscillatoria.jpg

Also, while ago I isolated Oscillatoria princeps from Yellowstone hot spring. Diameter and shape of cells were very similar. Your sample look like dehydrated?

It is most likely Calothrix contarenii, which is a heterocystous cyanobacteria frequently occuring on intertidal rocky shores. At the base of the filament the special cell called heterocyst presents. The pictures revealed severely stressed filaments. It may be Dichothris sp. as well depending on branching pattern and position of heterocysts. But, from these pictures it is most likely calothrix sp. If possible, you may want to send the sample for proper identification. This cyanobacteria grows in less nitrogen environment.

I agree with Sushanta Saha. I think, that this species belong to Nostocales. The filaments look like heteropolar trichoms with the simple apical heterocyst (the last little smaller and wider, look like "empty" cells). In my opinion it may be Calothrix sp. or Rivularia sp. I'm quite sure that is not Lyngbya. Lyngbya has isopolar trichoms and firm sheats.

I think this sample may be related to calothrix or related genera.The sample showed a young basal heterocyst with attenuation to the filament across the whole length.

At first glance it seemed to me that this is Nodularia sp. I am not familiar with marine species but, if we reconsider the shape due to decomposition, it may as well be Nodularia. You should find more fresh samples or recheck the preservative solution since the filaments seem decomposed.

Calotrix sp. have average diameter about 10 microns! Oscillatoria is about 20-25 microns.

This is a filamentous form with a terminal heterocyst.

Calothrix is the most probable genus. Difficult to see if false ramification were formed.

The origin of the strain and information on the sample (culture or sample collected in situ ?) would be useful. Where was it growing ? This may help for a more reliable determination. See

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

However the site is in French !

I attach an old course in english in which you will find a simplified key of genera determination.

Pierre Armand Roger ([email protected])

I think there are 2 possibilities: Tolypothrix sp. or Calothrix sp. I would go with the first.

thank you all, very much

The sample was collected as a clone from the intertidal rock so it is mixed with grains of sand, I now belive that the clone cntains 2 species: Lyngbya (probably L. aestuarii) and Calothrix (mabe C. contarenii). As for the diametric data, I look at the key for Calothrix in Framy book and some species reach the 20-25 microns.

C. contarenii should have basal filament diameter up to 15 microns. so because of size this could be a different species. Does it have terminal hair?

A better picture would be fine.

Dear Tomas sorry for the pic quality

I tries to clean the sample of the grains.

As I said before, Take a look at Framy book species of this genus range between 5 -25 microns.

Yes, I believe it's Calothrix too, especially because of the diameter!

One more thing, It looks like this species has terninal hair. Please look at the right side of fig 2 (6)

It is more of Tolypothrix

The material is very deformed but I wonder if it is by dehydration or culturing?.

it is necessary to have a better picture to observe if it has basal heterocytes and terminal attenuation. the other pictures show also very long deformed filaments where you have to look for real attenuation, sheath characteristics or heterocytes. I suggest to preserve as soon as possible after collection in 4% formaline in seawater to avoid deformation.

I also agree with Sushanta Saha and others: Calothrix. New heterocysts and incipient false ramifications (at heterocyst level) seems to to be starting to diferenciate in the upper filament of fig. 1.

See Calothrix picture at http://www.flickr.com/photos/48626723@N05/4456329334/

Click on the picture

Thank you Carlos, you marked the hetrocytes but what is your diagnosis?

Razy, I think that an accurate description is more useful than a name. Good and as complete as possible observations (and also informative images, in this case) are needed to ask the specialists about the identity of an an organism. Good observations and fine documentation survive the ages (!). Names come and go according with the advance of taxonomic knowledge. As a matter of fact I did not find the heterocysts. I pinpoint the "modules" (heterocysts and false ramifications) that will result into a new trichomes with their basal heterocysts. I.e. the basic of ontogeny of Rivulariaceae. If it is not interesting for you, it could be so for other people of this forum. I am out of my lab just now (summer holidays). When I come back to work I will look for the name you need in the taxonomic literature. However, I am sure there is very trained taxonomists in RG that can do this in the meantime. Good luck!

Regarding the hair formation in Rivulariaceae see https://www.researchgate.net/publication/233466388_Influence_of_nutrient_deficiency_on_hair_formation_in_the_Rivulariaceae

Article Influence of nutrient deficiency on hair formation in the Ri...

Thank you very much Carlos. I will be waiting for your diagnosis. the sample came from the upper intertidal and was probably not fresh at all! I think that you are right concerning the lack of heterocyte. It should be trichome that was seperated from the others and changed position in space!! Have a nice holiday

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.

It seems to me, that the cyanobacterium is not taperiring towards the end, so it can not be Calothrix. I would thing abou some Tolypothrix or Hassallia.

As mentioned Pierre Roger, the reference book for prokaryota is Bergey's manual, but for Cyanobacteria it is quite doubtful source. At least because of age of last edition.

Thank you Pierre and Tomas

Tomas, you ignore fig2. This fig show that the sample is taperiring towards the end.

The SOLE source for identification will be the collected works by Jiri Komarek who at the request of the International Botanical Congress began a complete taxonomic assessment of the cyanoprokaryotes. The third volume volume was just published and the series was initiated with Cyanoprokaryota: Teil 1 / Part 1: Chroococcales (Süßwasserflora von Mitteleuropa) [German] [Paperback]. This photo appears to have false branching, e.g. Scytonema but a better set of pictures would help. Best of luck! PZ

Thank you Paul

The filaments show terminal heterocyst and some tapering is also visible as also minor indication of false branch formation. This can be Calothrix species but doubt arises keeping in view the breadth and length of the cells. One needs to keep option for apical cell distinction into something like visible in photo , a feature which may change the whole identification to some oscillatorian genus! Culturing of material can clear the problem associated with development of cyanoprokaryotes.

Razy

Phormidium sp. / Oscillatoia sp see (Entwisle et al., 1997; Janse Van Vuuren et al., 2006).

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