Clupeid fish are a type of fish that belong to the family Clupeidae. These fish are commonly referred to as herring, sardines, or shads. The term "clupeid fish" is often used to describe a wide range of fish species, including some of the most important commercial fish in the world. Some of the synonyms for clupeid fish include anchovies, pilchards, menhaden, and sprats. These fish are typically small, oily, and rich in nutrients, making them an important food source for many marine and terrestrial animals. They are also important commercially, with many countries relying on them as a key export.