Cladocera are small, freshwater crustaceans commonly known as water fleas. They belong to the class Branchiopoda and are characterized by their transparent bodies and large, compound eyes. Cladocerans play a crucial role in aquatic ecosystems, serving as a food source for fish and other predators. These organisms have a unique body structure, often featuring a carapace that covers their body and a pair of antennae used for swimming. Cladocera reproduce both sexually and asexually, with some species capable of producing eggs that can withstand harsh environmental conditions, ensuring their survival in fluctuating habitats.