Feed items include both epipelagic and mesopelagic species, with deep diving behaviour during the day thought to be related to the seeking of prey.
Longer-lived than the closely related yellowfin tuna, the bigeye is thought to have a lifespan of up to 12 years, with sexual maturity at the age of four. Spawning takes place in June and July in the northwestern tropical Atlantic, and in January and February in the Gulf of Guinea, which is the only known nursery area for Atlantic bigeye.
Satellite tagging showed that bigeye tuna often spend prolonged periods diving deep below the surface during the daytime, sometimes as deep as 500 metres (1,600 ft). Bigeye have been tracked entering water as cold as 5 °C (41 °F). These movements are thought to be in response to vertical migrations of prey organisms in the deep scattering layer.
Bigeye tuna are found in the open waters of all tropical and temperate oceans, but not the Mediterranean Sea.