Starter Culture about 100 daphnia. Daphnia magna is a species of freshwater crustacean, commonly known as the water flea. It belongs to the order Cladocera within the class Branchiopoda. Daphnia magna is widely used in scientific research, particularly in ecotoxicology and environmental studies, due to its sensitivity to various environmental stressors and pollutants. It's also utilized in studies related to ecology, evolution, and genetics. Daphnia magna is frequently used as a model organism because of its transparent body, rapid reproduction rate, and ease of culturing in the laboratory. These characteristics make it valuable for studying various biological processes and responses to environmental changes.