Are All Antarctic Animals Cold-Blooded?

No. Antarctica hosts both warm-blooded (endothermic) and cold-blooded (ectothermic) animals.

Warm-Blooded (Endotherms)

• Penguins (Emperor, Adélie, Chinstrap, Gentoo) – feathers, fat, counter-current heat exchange.
• Seals (Weddell, Leopard, Crabeater, Ross, Elephant) – blubber, fur, vascular control.
• Whales (Blue, Fin, Humpback, Minke, Orca) – blubber, massive thermal inertia.
• Seabirds (Petrels, Skuas, Albatrosses, Skuas) – feathers, high metabolism.

Cold-Blooded (Ectotherms)

• Antarctic fish (Notothenioids – "icefish"): Antifreeze glycoproteins (AFGPs) prevent blood freezing at -1.9°C.
• Invertebrates: Nematodes, tardigrades, rotifers, springtails, mites – cryptobiosis, trehalose vitrification.
• Krill (Euphausia superba) – key food web base; supercooling, metabolic suppression.

Adaptations Summary

Antarctica's extreme cold selects for specialized physiology in both thermal strategies.