a red Blue-Green alga

Franz Neidl · Post by **Franz Neidl** » Thu Sep 16, 2010 8:45 am

I found in marine plancton this red blue-green alga (Bacteriophyceae). The filaments were 5 µm thick. I think this is an Oscillatoria, but I am not shure. Somebody can help me?
Two pictures with obj. 40X, DIC

Franz

Charles Krebs · Post by **Charles Krebs** » Thu Sep 16, 2010 1:39 pm

I like the second image a great deal.

Can't really help with the ID, but I don't see a distinct mucilage "sheath", which would rule out some other similar looking cyanobacteria.

fpelectronica · Post by **fpelectronica** » Thu Sep 16, 2010 1:53 pm

Hello Franz
Phormidium?
Francisco

Mitch640 · Post by **Mitch640** » Thu Sep 16, 2010 1:54 pm

Great images Franz. Do you know what the red comes from? Very neat looking twisted algae in #1.

uaalgae · Post by **uaalgae** » Sun Jan 08, 2012 9:21 pm

Blue-green algae have two special water-soluble pigments - phycocyanin and phycoerythrin. The first pigment combined with chlorophyll a gives the algae a blue color. Under stress, the blue-green may express more phycoerythrin which will turn the alga red. Red algae have a lot of phycoerythrin and is therefore very red.

a red Blue-Green alga

a red Blue-Green alga

red color