FIGURE 2.

Microscopic images of Oscillatoria filaments collected from benthic mats at El Cajon Bay and Middle Island Sinkhole, Lake Huron. Top left: Low magnification digital camera image of the dispersion of individual filaments form a recently formed aggregation of Oscillatoria in a petri dish; Top right: low magnification microscopic image showing Oscillatoria filaments in a freshly collected mat sample from Middle Island Sinkhole; Bottom left: medium magnification microscopic image of Oscillatoria filaments; Bottom right: high magnification microscopic image of Oscillatoria filaments, with pigmented smaller filaments likely representing the cyanobacteria Phormidium, and the non-pigmented smallest filaments likely to be chemosysnthetic bacteria or archea.