Branchiostomidae is a family of jawless fish commonly known as lancelets. These fish are small and slender with a translucent body and can be found in many parts of the world. While the term Branchiostomidae is the scientific name used to refer to this group of fish, there are a few synonyms that can be used interchangeably. These alternatives include Amphioxidae, Amphioxus, or the lancelet family. The name Amphioxus comes from Greek words that mean "both ends pointed," referencing the fish's tapered body shape. Regardless of the terminology used, these small, primitive fish play an important role in the ecosystem and have been studied extensively for their unique characteristics and evolutionary history.