Photosynthetic and behavioral versatility of the cyanobacterium Oscillatoria boryana in a sulfide-rich microbial mat

The diel pattern of vertical migratory movements and photosynthetic activity of O. cf. boryana was monitored periodically in microbial mats of a shallow tepid pond fed by sulfide-rich, hot, geothermal spring water in Rotorua, New Zealand. Motile O. boryana formed a conspicuous and predominant population which was spread over the mat surface during darkness and on overcast days (300 W m super(-2)), O. boryana disappeared almost entirely form the mat surface to a position of about 1 mm below the surface pellicle of the mat.