Single-celled organisms (singular = cyanobacterium) similar to bacteria, except cyanobacteria contain the green pigment chlorophyll (as well as other pigments), which traps the energy of sunlight and enables these organisms to carry on photosynthesis. Cyanobacteria are autotrophic producers of their own food from simple raw materials, whereas bacteria are heterotrophic decomposers of the wastes and bodies of other organisms. Cyanobacteria were formerly known as blue-green algae. Blooms or population explosions of cyanobacteria cause water pollution. Some cyanobacteria-like bodies (CLBs) have been associated with causing waterborne diarrheal illnesses.