Do you know that goldfish are able to survive for months in oxygen-free water? In fact, crucian carp family (goldfish included) can survive without oxygen for longer period.

The fish convert their anaerobically produced lactic acid into ethanol (alcohol) which diffuses across their gills into the surrounding water.

Do you also know that the blood alcohol concentration in these fish can exceed the drink-drive limit during the winter?

During their time in oxygen-free water in ice-covered ponds, which can last for several months in their northern European habitat, blood alcohol concentrations in crucian carp can reach more than 50mg per 100 millilitres,” said by Dr Michael Berenbrink, an evolutionary physiologist at the University of Liverpool.

Lead author Dr Cathrine Elisabeth Fagernes, from the University of Oslo, said: “The ethanol production allows the crucian carp to be the only fish species surviving and exploiting these harsh environments.

“It’s no wonder then that the crucian carp’s cousin the goldfish is arguably one of the most resilient pets under human care.”

Learned something new. FP worthy
Thanks OP