Rotifera are a phylum of microscopic, aquatic animals commonly found in freshwater environments, such as ponds and streams. They are characterized by their wheel-like structures, called corona, which they use for locomotion and feeding. Rotifers play an essential role in the ecosystem by contributing to the food web and helping to decompose organic matter. These tiny creatures typically range from 0.1 to 0.5 millimeters in size and possess a complex body structure, including a head, trunk, and foot. Rotifera reproduce both sexually and asexually, with some species capable of surviving extreme conditions through a process called cryptobiosis, allowing them to endure desiccation and freezing temperatures.