Page 8 - BBC Knowledge - October 2017 IN

Q

Questions
& Answers Dr Alastair Gunn Dr Helen Scales
A
& Environment/ climate expert Oceans expert, science writer

Astronomer, astrophysicist
Prof Robert Matthews
Alex Franklin-Cheung
Physicist, science writer
Dr Peter J Bentley
Luis Villazon
Computer scientist, author
Science/tech writer
Prof Mark Lorch
Prof Alice Gregory
Chemist, science writer Psychologist, sleep expert

YOUR QUESTIONS ANSWERED

WHY DO SOME FISH HAVE
COLOURLESS BLOOD?

Antarctic icefish have colourless blood with no red blood cells and
no haemoglobin, the oxygen-carrying pigment. This probably comes
down to a genetic mutation, and means their blood carries 90 per
cent less oxygen than red blood. They survive partly because
frigid Antarctic waters are oxygen-rich. Icefish also have enormous
hearts that pump huge volumes of blood around their bodies,
making sure they get enough oxygen. Antifreeze in their blood stops
them from freezing (the salty Southern Ocean gets down to -2°C)
but, as they are so well-adapted to the cold, their future in
a warming world remains uncertain. HS
8
OCTOBER 2017