The southern bluefin tuna, like other tuna species, has a very thin gas-exchange membrane. Tunas have a barrier thickness of 0.5μm, compared with 10μm of dogfish, 5μm of toadfish and less than 5μm of trouts. This means that the oxygen must diffuse a short distance across the respiratory surface to get to the blood. Similarly to the increased surface area, this allows the highly metabolic organism to take oxygenated blood into the circulatory system more quickly. On top of a quicker rate of diffusion in the respiratory system of southern bluefin tuna, there is a significant difference in the efficiency of the oxygen uptake. While other teleost fish typically utilize 27–50% of the oxygen in the water, the tuna's utilization rates have been observed as high as 50-60%. This overall high oxygen uptake works in close coordination with a well-adapted circulatory system to meet the high metabolic needs of the southern bluefin tuna.