Commonly known as the longtail tuna or northern bluefin tuna, Thunnus tonggol is distinct from true bluefins like Thunnus thynnus and Thunnus orientalis. Identified by its slender build and shorter pectoral fins, it reaches up to 145 cm and 35.9 kg. Characterized by slower growth and a longer lifespan, there’s concern about its vulnerability to overfishing, especially in Australia where it’s distinguished from the southern bluefin tuna.