Water Flea with eggs - Daphnia pulex - This most common species of water flea belongs to the family Daphiniidae. It has a cosmopolitan distribution in a wide range of aquatic habitats, although it is most closely associated with small, shaded pools and lakes of an oligotrophic nature. (Their range extends across most of the world - Americas, Europe & Australia - in appropriate habitats, most of which offer little by way of nutrients)
Diatoms are a major group of algae, and are one of the most common types of phytoplankton. Most diatoms are unicellular, although they can exist as colonies in the shape of filaments or ribbons, fans, zigzags, or stellate colonies.