SeaLab: Antarctica: The Mission
Image: Fish
Pelagic Fish

>> SPECIES DIVERSITY: Only a very small portion of the world’s 20,000 known species of fish live south of the Antarctic Polar Front—about 120. Many of these 120 species are found only here.

>> CLASSIFICATION: The order Notothenioidea makes up 75 percent of Antarctic fish. Most of these are small fish with spines along their back and large pectoral fins. The Antarctic cod is the largest and can weigh up to 150 pounds (70 kilograms).

>> KRILL DEPENDENCE: Most of the Antarctic fish are sea-bottom dwellers. Many pelagic (open-water) fish that live in the middle depths feed on krill, as do fish that travel to the surface to feed. Many fish groups are dependent on the shrimplike crustacean.

>> ADAPTATIONS: To survive the near-freezing waters, most Antarctic fish have evolved a unique adaptation—antifreeze proteins called glycoproteins in their blood and body tissues.


Photograph by Scott Kerrigan
© 2001 National Geographic Society. All rights reserved.