Pacific bluefin tuna support a large commercial fishery. Tuna meat is driving overfishing as to endanger some species like the bluefin tuna. Atlantic bluefin tuna reach maturity relatively quickly. Bluefin tuna sashimi is a particular delicacy in Japan. Several fishing competitions targeting southern bluefin tuna are held annually. Atlantic bluefin tuna spawn in two widely separated areas. Yellowfin is becoming a popular replacement for the severely depleted supplies of southern bluefin tuna. These upwellings support lucrative fisheries, including that of the southern bluefin tuna and sardine. Heat exchange in southern bluefin tuna is a unique adaption among teleost fishes. At maximum length, the albacore is the smallest of the bluefin tuna. Japan first successfully farm-hatched and raised bluefin tuna in 1979. About 80% of the caught Atlantic and Pacific bluefin tunas are consumed in Japan. Ceduna is also a hub for research on southern bluefin tuna. This regulation of an internal ion concentration classifies southern bluefin tuna as osmoregulators. The Convention created the Commission for the Conservation of Southern Bluefin Tuna (CCSBT).