Daphnia are tiny crustaceans and are sometimes called water fleas. But unlike fleas they are nearly transparent, live in water, have a shell, and are graced with an interesting array of modified appendages for sensing, feeding, and swimming. As they travel they filter even tinier organisms from the water. They feed on single-celled algae, yeast, and bacteria. Daphnia in turn are eaten by fish and aquatic insects. Daphnia is the common organism that is used for testing water toxicity.
An excellent freshwater crustacean for viewing heartbeat, live birth and toxicity tests. Please call for School District Bulk Pricing.
One way to test for the presence of toxic compounds in a water sample is a bioassay. In a bioassay, a living organism serves as a detector for toxins—the same way canaries were used in coal mines to detect invisible toxic gases. In this project, water fleas (Daphnia magna), a freshwater crustacean, are used in a bioassay to monitor water quality. Many variations of this experiment are possible.
There are at least 30+ daphnia in each jar.