They swim the ocean waters from the surface down to a depth of about 250 m. They have been found in waters between 13 and 29°C, but their optimum range is between 17 and 22. This coincides with the permanent temperature range of the thermocline. They abound in tropical waters and share their habitat and, even their shoal, with smaller tunas such as yellowfin.
Seventeen countries around the world report their catches annually. This amounts to a total of over 10,000 metric tons every year in five fishing areas, with more than two-thirds of the total fish caught in the Pacific. Japan ranks first place, followed by the Republic of Korea, with much smaller catches.
The most common size of a bigeye tuna is two metres long, the length that they reach at the age of three. The largest specimen caught since records began was a fish weighing 197 kg and measuring 236 cm in length, caught in Cabo Blanco, Peru.