Fish Have Special Qualities That Keeps Them Alive Even In Icy Water, New Experiments Reveal

Scientists have discovered the reason why fish will not freeze to death in icy water. The waters of the Antarctic and Arctic Oceans are cold enough to freeze the blood of a fish. New experiments reveal, however, that fish have special qualities that keeps them alive even in icy water.

Live Science reveals that fish have special frost protection proteins in their blood that protects them from freezing to death in cold water. The Antarctic Ocean has a freezing temperature of 28.8 degrees Fahrenheit which is lower than the freezing point of fish blood of 30.4 degrees Fahrenheit. The ability of the fish to survive in these conditions have puzzled scientists for over 50 years. The anti-freeze protein found in fish blood is more effective than any household antifreeze.

To investigate the antifreeze properties of fishes, researchers from the Ruhr University Bochum in Germany studied the Antarctic toothfish (Disssoctichus mawsoni) caught by one of the American partners, Arthur Devries, while on an expedition in the area. They used a special technique to record the movement of water molecules mixed with antifreeze proteins from the fish. They discovered that these proteins disturb the water molecules to keep them from bonding together and form ice crystals.

Science Daily reports that the researchers utilized a special technique called terahertz spectroscopy in investigating how the antifreeze protein in fish blood works. Using terahertz radiation, the collective motion of water molecules and proteins can be recorded. "We could see that the protein has an especially long-range effect on the water molecules around it. We speak of an extended dynamic hydration shell," said study co-author Konrad Meister.

The research team was headed by Prof. Dr. Martina Havenith together with cooperation partners from the US. The findings were described in the Aug. 16 edition of the Journal of the American Chemical Society (JACS). The research was funded by the Volkswagen Foundation.