Research
on this has been done on antarctic fish. Apparently, there are "antifreeze" proteins in the fish blood stream. These proteins don't reduce the freezing point of the blood (that would take an intoxicatingly high concentration of chemical) but instead they attach to the surface of microscopic ice crystals and interfere with the growth.
Slashdot Mirror
Research on this has been done on antarctic fish. Apparently, there are "antifreeze" proteins in the fish blood stream. These proteins don't reduce the freezing point of the blood (that would take an intoxicatingly high concentration of chemical) but instead they attach to the surface of microscopic ice crystals and interfere with the growth.
"You'd have to find a mountain duck," said Professor Cox
Found one!