The Southern Bluefin Tuna is is a large predatory fish that lives in the open oceans south of the equator. It is the smallest of the 3 species of bluefin tunas but the one closest to extinction. Like other tunas, it is a torpedo shaped, incredibly fast fish that is able to keep certain muscle groups above ambient seawater temperatures through the use of heat exchangers, high metabolism and the phenomenon of gigantothermy.
Here are some neat facts & FAQ on the Southern bluefin tuna:
How many species of bluefin tuna are there?
There are 3 (by average size, large to small):
Which bluefin species is the largest and smallest?
The Atlantic bluefin tuna is the largest while the Southern bluefin tuna is the smallest (some 3x smaller).
What is the average weight of the Southern bluefin tuna?
100-200 pounds but can reach 570 pounds.
What is the average length of the Southern bluefin tuna?
3-5 feet but can reach 8 feet.
Are Southern bluefin tuna divided into separate stocks?
No. Of the 3 species of bluefins, only the Atlantic bluefins are divided into separate stocks.
What is the population of the Southern bluefin tuna?
In 2009 there were an estimated 460,000 mature Southern Bluefin Tuna.1
Where is the Southern bluefin tuna found?
All oceans in the southern hemisphere. Juveniles live near shore but after 5 years of age they live in the open ocean.
How long do Southern bluefin tuna live for?
Where do Southern bluefin tuna spawn?
South of Java between September and April.
Do Southern bluefin tuna migrate?
Yes, they migrate to waters south of Java for spawning and between the cooler and warmer waters off Australia and the Indian ocean.
What’s the difference between the Southern bluefin tuna and their northern counterparts?
The Southern bluefins have a yellow median caudal keel that is dark in the Bluefin Tuna. Southern Bluefin Tuna also have a longer adult pectoral fin (20–23% of length to caudal fork compared with 17–22% in the 2 northern species (Caton 1991).
What is the largest Southern bluefin tuna ever caught?
The all-tackle world record is 369 pounds in 2009 2. Commercially caught Southern bluefins have reached 570 pounds.
Is the Southern bluefin tuna warm blooded?
All bluefins are lukewarm blooded as explained here.
How fast do Southern bluefin tuna swim?
Up to about 30 mph.
What do Southern bluefin tuna eat?
Like all bluefins, they are opportunistic predators, feeding on most anything they can catch but mostly sardines, mackerel and squid.
Do Southern bluefin tuna have any predators?
Young Southern bluefin tuna are vulnerable to any predators larger than them like sharks and other tuna.
Is the Southern bluefin tuna endangered?
Yes. They are considered critically endangered; the only status left before extinction. IUCN Status