Southern bluefin tuna weigh over 200kg; and grow over 2m. Lifespan is 20 to 40 years.
Bluefin tuna are built like torpedoes. Not only do they have a hydrodynamic shape, their pectoral (side) fins can be retracted and their eyes are set flush to their body. This means their bodies create little drag as they swim through water. A warm body temperature also helps these fish swim fast, as does a stiff body that channels muscle energy directly to a highly efficient, crescent-shaped tail.
Habitat and Distribution
Southern bluefin tuna are found throughout the southern Atlantic, Pacific and Indian Oceans – generally south of 30 degrees south, though they do head north to the warm waters south of Java to spawn between September and April.
Southern bluefin tuna reach reproductive maturity between 8 and 12 years, although few are allowed to reach this age.