Water fleas are small crustaceans that live in freshwater bodies. They are called by different names depending on the region, for example, Daphnia, Cladocera, or Branchiopoda. These tiny creatures are an important part of the aquatic food chain, as they are a primary food source for fish and other larger creatures. Some other synonyms for water fleas include planktonic crustaceans, small aquatic arthropods, and freshwater zooplankton. Depending on the context, water fleas can also be referred to by their specific species names, such as Daphnia magna and Ceriodaphnia dubia. Regardless of their name, water fleas are fascinating creatures that play a crucial role in maintaining the health and balance of freshwater ecosystems.