Goldfish turn to alcohol to survive harsh winter in icy lakes

Humans and most other vertebrate animals die within a few minutes without oxygen. Yet goldfish and their wild relatives, crucian carp, can survive for days, even months, in oxygen-free water at the bottom of ice-covered ponds. 

During this time, the fish are able to convert anaerobically produced lactic acid into ethanol, which then diffuses across their gills into the surrounding water and avoids a dangerous build-up of lactic acid in the body. 

Scientists at the University of Oslo in Norway and University of Liverpool in the UK found the molecular mechanism behind this highly unusual ability, which is unique among vertebrates and more commonly associated with brewer’s yeast.