The species resembles Thunnus albacares but lacks greatly elongated lobes in the second dorsal and anal fins. There are 19–27 gill rakers on the 1st gill arch and it does not possess a swim bladder. The coloration includes a dark blue or black back with the dorsal, pectoral and pelvic fins appearing blackish.Tips of the second dorsal and anal fins have a yellowish wash while the anal fin appears silvery. The caudal fin is blackish with streaks of yellowish green.