Antarctica boasts a diverse range of fish species that are supremely adapted to their unique and harsh environment.
Many Antarctic fish species, particularly in the Notothenioids suborder that makes up the majority of Antarctic fish species, make their own antifreeze that enables them to survive Antarctica’s cold waters.
Members of the icefish family lack hemoglobin, the protein that most vertebrates use to transport oxygen in their blood. Instead, they are able to absorb oxygen directly from the surrounding water.
Some fish species are adapted to live their entire lives near the deep seafloor and lack swim bladders, the gas-filled organs used by most fish to adjust their buoyancy. Other species have developed special fat reserves to provide the neutral buoyancy they need to lay their eggs directly under the sea-ice.
Each Antarctic fish species plays an important role in the food web, many as prey items for animals like seals, whales, colossal squid and penguins.
The unique life histories and habitat use of most Antarctic fish are not well understood. Some of these species share a common set of characteristics – they are slow growing, late maturing and long lived. Whether exploited directly or taken as bycatch, these characteristics make populations of these fish species highly susceptible to being overfished. Because these species are particularly well adapted to the unique conditions of the Antarctic, they are expected to be very sensitive to small changes in climate as well as sea-ice loss.