Stigonema Mammilosum

[hkv]

This photograph shows a beautiful (and relatively large) terrestrial cyanobacteria often found growing on rocks. Stigonema Mammilosum is a short branching species that can be found as blackish crusts and biofilms on inselbergs (isolated rock hill, knob or ridge) in many places on earth. Alexander von Humboldt, a Prussian naturalist and explorer, described but misinterpreted the reason for these black crusts and wrote in 1849 that certain rocks seems to:

“develop a greyish-black cover which does not penetrate more than 0.01 line (0.02mm) into the interior of the rock… the sheath appears to contain manganese oxide and carbon”.

Due to the fact that the species can grow on rocks, they can survice without water for extensive periods of time. Also, they have the ability to adapt to high light intensities, unlike many other species of cyanobacteria. When rain falls, photosynthetic activity is restored within 60 minutes after rewetting following desiccation.

This sample was isolated from fully exposed rocks in Switzerland. Stigonema Mammilosum is a filamentous cyanobacteria with true branching (similar to plants) which gives it its characteristic appearance.


Stigonema_Mammilosum_DIC_2_2048 by Håkan Kvarnström, on Flickr


Stigonema_Mammilosum_DIC_3_2048 by Håkan Kvarnström, on Flickr


Stigonema_Mammilosum_DIC_1_2048 by Håkan Kvarnström, on Flickr


Stigonema_Mammilosum_Fluo_1_2048 by Håkan Kvarnström, on Flickr

[viktor j nilsson]

Truly spectacular photos, Håkan.

Inselberg is such a delightful word, too.

[75RR]

Beautiful images ... you have raised the bar!

[sinabro]

Wow, very very nice hkv...

[KD Arvidsson]

Woow i get jealous, great job hkv //KD

[KurtM]

Truly spectacular photos, Håkan.

Inselberg is such a delightful word, too.

Indeed!

Wonderful post, thank you Håkan. Please accept this Uber Geek Award all the way from Texas --->

[hkv]

Thanks all! It is truly an interesting species but difficult to culture. I have them in a petri dish, but they are not growing at the moment. Also have a batch in culture growth media with very limited growth. Trying to make a few more strands to photograph. Will try using an oil objective. These very taken with a water immersion objective so I should be able go get better resolution and detail with the oil NA1.45 (if I can get enough working distance).

[75RR]

These very taken with a water immersion objective so I should be able go get better resolution and detail with the oil NA1.45 (if I can get enough working distance).

Looking forward to that!

[RobBerdan]

Beautiful photomicrographs.
RB