Fish
Antarctic Toothfish
Dissostichus mawsoni · also called Antarctic cod
Circulating natural antifreeze through its own blood, an Antarctic toothfish survives sub-zero Southern Ocean water that would freeze most other fish solid, growing large enough to become a key meal for colossal squid, sperm whales, and seals alike.
Overview
The Antarctic toothfish, Dissostichus mawsoni, is a large, cold-adapted fish native to ocean and polar habitat across the Southern Ocean surrounding Antarctica. Its remarkable antifreeze blood proteins, considerable size, and central role as prey for some of the ocean’s largest predators make it one of the most ecologically important fish species found anywhere in Antarctic waters.
A fish built to survive freezing water
Where most fish would freeze solid in the sub-zero water surrounding Antarctica, the Antarctic toothfish circulates natural antifreeze proteins through its blood, an adaptation that has allowed it to thrive in one of the coldest marine environments on Earth.
Status
Least Concern, managed under an international fishery quota system, though detailed population trends across its full Southern Ocean range remain uncertain.
Antarctic Toothfish: common questions
How does the Antarctic toothfish survive in freezing water?
This species produces natural antifreeze glycoproteins that circulate in its blood, preventing ice crystals from forming even in the sub-zero temperatures typical of Southern Ocean water, an adaptation shared with several other Antarctic fish species.
What eats the Antarctic toothfish?
This species is a significant prey item for large predators such as the colossal squid, sperm whales, and various seal species, playing a central role in transferring energy through the Southern Ocean food web.
Why is the Antarctic toothfish slow to recover from overfishing?
This species grows slowly and can live for several decades, a combination that makes populations slow to rebuild once reduced by heavy fishing pressure, requiring careful management of the commercial fishery.
Where in the ocean is the Antarctic toothfish typically found?
This species is found both near the seafloor and in the open water column, adjusting its position depending on its age and the availability of prey across its Southern Ocean range.