Algae ID

[saltyhog]

I have this interesting algae in my tank. It's usually on the sand bed and usually associated with some cyano. It's almost perfectly round, doesn't move and has no apparent internal structures. Any ideas? @taricha

 

[taricha]

There's a few people who have had cells like that show up. Spherical totally motionless, green or red / pink, single cells. I've had a pink form. My best guess is that this is an uncommon form of cyanobacteria. This wild speculation is based on the fact that these very similar looking cells can show up either green or red / pink, indicating they may possess the cyano palette of pigments. Also cyanobacteria are so absurdly diverse, that any possible cell form and niche you can imagine - there is a cyano that does it.

 

[saltyhog]

There's a few people who have had cells like that show up. Spherical totally motionless, green or red / pink, single cells. I've had a pink form. My best guess is that this is an uncommon form of cyanobacteria. This wild speculation is based on the fact that these very similar looking cells can show up either green or red / pink, indicating they may possess the cyano palette of pigments. Also cyanobacteria are so absurdly diverse, that any possible cell form and niche you can imagine - there is a cyano that does it.

That is VERY interesting. One reason it is interesting is that this stuff is almost always intertwined in mats of cyano. That's the only place I see it! Thanks @taricha!