Genus Euthynnus is a family of fish species that includes several common types of tuna. In scientific circles, the genus is commonly referred to as Katsuwonus, which is derived from the Japanese word for skipjack tuna. Other synonyms for the genus include Kishinouyea, Parathunnus, Pelamys, and Thunnus (which is the genus name for bluefin tuna). While these different names may seem confusing, they all refer to the same group of fish. Regardless of the label used, members of the Genus Euthynnus can be found in many oceans across the world, and are an important source of food and sport for many cultures.