Fish
Antarctic Silverfish
Pleuragramma antarcticum · also called Antarctic herring
Small enough to be overlooked entirely, an Antarctic silverfish nonetheless holds together much of the Southern Ocean food web, feeding penguins, seals, toothfish, and whales alike as one of the most abundant fish species found anywhere around the frozen continent.
Overview
The Antarctic silverfish, Pleuragramma antarcticum, is a Least Concern fish native to ocean and polar habitat across coastal and continental shelf waters surrounding Antarctica. Its central role as prey for a vast range of predators, its unusual open-water lifestyle, and its antifreeze-protected blood make it one of the most ecologically important fish species found anywhere in the Southern Ocean.
The fish that feeds a continent’s wildlife
Rarely seen and easily overshadowed by the predators that depend on it, the Antarctic silverfish quietly underpins an entire food web, converting plankton into a form of energy that penguins, seals, toothfish, and whales all rely on in turn.
Status
Least Concern, remaining abundant across most of its range, though considered sensitive to future changes in sea ice conditions linked to a warming Southern Ocean.
Antarctic Silverfish: common questions
Why is the Antarctic silverfish so important to the Southern Ocean food web?
This species is one of the most important prey species in the Southern Ocean, feeding an enormous range of predators from penguins and seals to toothfish and whales despite its own relatively small size.
How does the Antarctic silverfish survive 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.
Where does the Antarctic silverfish live in the water column?
This species spends nearly its entire life in the open water column rather than near the seafloor, an unusual habit among Antarctic fish that most other species do not share.
Why is the Antarctic silverfish considered vulnerable to climate change?
This species relies on sea ice for part of its early life cycle, making its population sensitive to changes in ice conditions linked to a warming Southern Ocean, even though it remains abundant today.