By finding morphological criteria for death in photosynthetic algal cells, one finds that the death of different populations of algae cells is manifested by various morphological changes. Present study, was undertaken to determine morphological criteria to be used in identifying cell death in unicellular green algae in their natural habitats. By applying the principles of formazan crystal formation due to MTT reduction in the presence of cells oxidoreductase enzymes, and the staining of saccharide complexes produced in photosynthesis by iodine reagent, morphological criteria were determined for cell death in Dunaliella salina collected from Maharloo lake and three different types of deaths were identified. Further studies have shown that these criteria can also be applied for fresh water algae and other taxon. Different ways of cell death in unicellular aquatic organisms can be used as monitoring tools for early warning of environmental hazards. We invite scientists, editors and reviewers to embark on establishing a much needed cell death classification committee for identifying different types of cell death and investigate mechanisms involved in unicellular aquatic algal cells.