Chroococcus, a unicellular organism that is a genus of cyanobacteria, is blue-green in color and macroscopic colony mounded. Within the outside sheath, microscopic colonies are found with indistinct trichomes. Chroococcus are usually found in colonies of two, four, or eight cells with a transparent protective covering sheath containing photosynthetic pigments. Like all cyanobacteria, Chroococcus is a prokaryote and therefore lacks any of the membranous organelles of eukaryotes. Known for its underwater habitat, Chroococcus prefers the sludge of lake and river bottoms to call home.