The algal layer, about three times as wide as a cortex, consists of tightly packed algal cells enveloped by fungal hyphae from the medulla.
A simple carbohydrate formed in the algal layer eventually is excreted, taken up by the mycobiont, and transformed into a different carbohydrate.
The algal layer is not continuous contrasting with lichen species that have thalli that stratify into discrete tissue types, including a photobiont layer and occurs with the mycobiont in the form of granules.
Algal cells were taken from the algal layer of U. subfloridana thalli and inoculated on the medium.
The amount of algae necessary to maintain a concentration of approximately 1.5 mg carbon L-1 in the algal layer was then calculated and the missing amount replenished.
With the increase of the cultivation days, the algal layers as well as the pigment content along the light path increased but the pigment content in each single cell decreased, and only a moderate decrease in light intensity happens when passing through each algal layer.
To collect Cyanidiales samples, we removed the surface rock using a hammer, and the cells were collected by scraping the thin algal layer into 50 mL Falcon tubes.
The algal cells layer was recuperated with a glass Pasteur pipette and filtered on a 0.45 μm filter previously dried and weighted.
Small Daphnia spread out in both directions, even into the region below the algal maximum (where food is still more abundant than in the epilimnion).
