The southern bluefin tuna, Thunnus maccoyii, is a cousin of the Northern Bluefin tuna and is found in southern hemisphere waters mainly between 30°S and 50°S, to nearly 60°S.  At up to 2.5 m (8.2 ft) and weighing up to 400 kg (882 lbs) it is one of the largest bony fishes.

The southern bluefin tuna is a large streamlined fast swimming fish with a long slender caudal peduncle and relatively short dorsal, pectoral and anal fins. The body is covered in small scales. The body colour is blue-black on the back and silver-white on the flanks and belly, with bright yellow caudal keels in adult specimens.

The southern bluefin tuna is an excellent sushi and sashimi meat, which is highly valued all over the world, but especially though in Japan.  In fact the only fish that commands a better price than southern bluefin is the northern bluefin tuna.

This fish is ranched commercially in South Australia, and annual output is 7000-8000 tons.  Most of this volume is consumed in Japan.  Atlantis is proud to market this fish world wide, thereby enhancing its product line of high end sushi and sashimi raw material.