Subclass Entomostraca belongs to the class Crustacea and includes a diverse group of small, primarily aquatic animals. They are characterized by their segmented bodies and jointed appendages. The subclass Entomostraca includes several groups, each with their own unique characteristics. Some synonyms for the subclass Entomostraca include "primitive crustaceans" and "microcrustaceans." Other related terms include "copepods," "cladocerans," and "ostracods," which are all different groups of Entomostraca. Many of these animals are important members of aquatic ecosystems, serving as food for fish and other aquatic organisms. Understanding the diversity and ecology of the Entomostraca is important for understanding the overall health of aquatic ecosystems.