The body size of insects is evolving in urban zones. Researchers in Belgium found the water flea’s (Daphnia magna) city variant was 44 percent smaller than its rural cousin. Larger forms of this water ...

Daphnia, also known as the water flea, is a small freshwater crustacean known for its sensitivity to pollution. To date, the impact of chemicals has been measured only at the whole organism level.

Except in appearance, the transparent little water flea called Daphnia magna is a good deal like a human being. In the words of Professor Arno Viehoever of the Philadelphia College of Pharmacy ...