The Blackfin Tuna (Thunnus atlanticus) is the smallest species in the genus Thunnus, inhabiting warm waters of the Western Atlantic, including the Gulf of Mexico and the Caribbean Sea. They are known for their dark blue to black backs and silver sides with a lateral yellow stripe. Blackfin Tuna are popular among sport fishers due to their size and fighting ability, and their flesh is considered comparable in taste and quality to other tuna species.