Ostracods are microscopic crustaceans that inhabit freshwater, marine, and terrestrial environments. There are various synonyms for this highly diverse group of organisms, including seed shrimps, mussel shrimps, ostracodes, and ostracans. The term "seed shrimps" refers to their small size and shrimp-like appearance, while "mussel shrimps" describes their bivalve-like shell. The terms "ostracodes" and "ostracans" are used interchangeably with ostracods to describe their membership in the subclass Ostracoda. Other synonyms for ostracods include Cypridina and Cytherina, which are two common genera of ostracods found in freshwater and marine environments. Overall, ostracods are a fascinating and important group of organisms with many different names and synonyms that reflect their diversity and complex biology.