Small algae

[gekko]

I think this may be Scenedesmus. DIC, 40x objective.

[JimT]

Maybe but not very green for "Green Algae".

[gekko]

Maybe but not very green for "Green Algae".

I agree. It may be because I used DIC (and, unfortunately, I didn't even look at them with BF, so I don't know what they really looked like). I think that sometimes green algae lose some of their green color (sometimes they appear brownish yellow, other times colorless) but I don't know what that means in terms of their chloroplasts. Perhaps someone can explain this.

[vasselle]

Bonjour gekko
Très belle image.
Merci pour le partage
Cordialement seb

[gekko]

Many thanks, seb.

[kinase]

Maybe but not very green for "Green Algae".

I agree. It may be because I used DIC (and, unfortunately, I didn't even look at them with BF, so I don't know what they really looked like). I think that sometimes green algae lose some of their green color (sometimes they appear brownish yellow, other times colorless) but I don't know what that means in terms of their chloroplasts. Perhaps someone can explain this.

Color's going to be dependent on which pigments they have. There's green and red algae, also brown and some other colors. The confusing part is that not all green algae are green, and the same is true for the other colors. The color designation they get comes from the presumed origin of the plastids and some genetics. Also maybe if its primary/secondary/tertiary/quaternary alga.

Chlorophyll a is green, b is a yellowish-greenish color, then there's also other pigments like phycoerythrin and that class which are more orange in color. Phycoerythrin makes a great fluorescent tag, it has a great quantum yield and is really bright.

Another thing that might happen is that really intense light will bleach the pigments and reduce the coloration. I don't recall if I've had that happen with white light but when I use a mercury lamp light source it's easy to destroy all the photosynthetic pigments.

[gekko]

Thank you, kinase, for explaining the color (or lack of color) in these green algae. I've seen this phenomenon in other cases too, and also in cyanobacteria. Good to have the explanation.

[75RR]

Nice image. Good detail on something that small.

[gekko]

Thank you, 75RR.