ACTIVITY 2 View the following representatives of cyanobacteria Identify unique structures e g heterocyst gelatinous material etc and describe the type of colonies e g filaments etc 1 Anabaena These cyanobacteria have round cells and forms simple filaments The heterocysts are slightly larger and less in number than the smaller more abundant vegetative cells Spores akinetes may also be present and are the largest of the three cell types found in this organism 2 Merismopedia These spherical cyanobacteria are mat forming Simple colonies consist of cells of various numbers often aligned in groups of twos or fours 3 Gleocapsa Like Merismopedia Gleocapsa also form colonies However the colonies are irregular spheres surrounded by a gelatinous material The cells appear encapsulated due to the gelatinous matrix This is why these cells are sometimes a challenge to view 4 Oscillatoria Oscillatoria cells are disk shaped and form very long filaments Darker cells in the filaments may be undergoing fission Pieces of the filament can break off and grow into a new filament When this happens a separation disk visible as a slightly lighter cell forms where the filament will break I Nostoc Nostoc cells are capable of secreting mucus thus creating a gelatinous matrix Similar to Anabaena these organisms have different specialized cells vegetative cells heterocysts