Alcohol found to be the remedy to surviving freezing temperatures.

To survive in the depths of frozen lakes, scientists have found that crucian carp – the untamed relative of the goldfish – turn to alcohol.

When trapped beneath the surface of frozen lakes and devoid of oxygen the fish remodel their anaerobically produced lactic acid into alcohol – or ethanol – which disperses across their gills. This capability distinguishes the goldfish from most vertebrates who would fall victim to such a harsh climate.

And with a blood alcohol concentration exceeding the drink-drive limit during the winter – at times more than 50mg per 100 millimetres – these vertebrates certainly do not hold back.

“The ethanol production allows the crucian carp to be the only fish species surviving and exploiting these harsh environments,” says Catherine Elisabeth Fagernes, from the University of Oslo. “Thereby avoiding competition and escaping predation by other fish species with which they normally interact in better oxygenated waters.

“It’s no wonder then that the crucian carp’s cousin the goldfish is arguably one of the most resilient pets under human care”, or is that just the alcohol talking?