Until recently, it was thought that there were seven Thunnus species, and that Atlantic bluefin tuna and Pacific bluefin tuna were subspecies of a single species.
Hingga akhir-akhir ini dipikirkan hanya terdapat tujuh spesies Thunnus, dan Tuna sirip biru Atlantik dan Tuna sirip biru Pasifik adalah dua subspesies dari spesies tunggal.