While we might often associate it with regrettable nights, alcohol isn’t always the enemy we make it out to be. In fact, in some instances, it’s healthy and even necessary for survival — at least for goldfish. In order to survive a winter without oxygen, goldfish produce alcohol to keep their gills functioning.
When vertebrates run out of oxygen, their cells turn to anaerobic respiration to produce energy. However, it creates lactic acid as an end product. Too much lactic acid is dangerous. Goldfish can survive without oxygen because they take this lactic acid and convert it into ethanol which flows across their gills out into the water.
Blood alcohol concentrations in goldfish can exceed 50 mg per 100 milliliters, which would surprise even a breathalyzer. But not to fear — the fish are not intoxicated. Even more mind-blowing, it allows the fish to live up to 5 months without oxygen. But how does it work?
The fish have two sets of the proteins that direct carbs to get broken down, which is essential to produce energy. The first set is nothing special… However, the second is activated when there isn’t any oxygen and directs substances to produce ethanol outside the mitochondria.
Eventually, the genome duplicated and mutation occurred. Remember, kids, watch your limit — unless you’re a goldfish.