Goldfish are a really resilient little species of animal. You can basically stick them into any environment and they survive. They may not thrive, but they do survive. Want to stick them in an aquarium with other fish? Go ahead. Want to throw them in a bowl and keep them on your desk at work? Go right ahead, all chances are they may outlast you or even the company you work for. You got sick of them and threw them into a nearby pond? No problem, they just became the biggest predator in the little pond and threw the pond’s entire eco-system out of balance.
A study from 2017 claims that this is due to the fish being alcoholics. Jokes aside, the fish, in fact, use a process that turns carbohydrates into alcohol. And fish are the only vertebrae that we know of so far that can do this.
If the fish finds itself in an area where oxygen is limited, inhalation starts a chain reaction that produces small amounts of energy for the muscles. Something similar happens in humans during exercise. If the muscle requires more oxygen than it can absorb, then the body creates it anaerobically. As a result, lactic acid begins to form. This is why we get sore and feel the burning sensation during exercise.
But instead of producing inordinate amounts of lactic acid in these conditions, Goldfish just turn the lactic acid into ethanol. This “drinking” habit is caused by secondary proteins that control energy production. The primary set of proteins is used in normal conditions, while this secondary one kicks in during anaerobic conditions.
Another reason for this is that lactic acid can potentially poison its host, especially during a five-month period spent underwater with limited oxygen supplies. This is why the fish convert it into ethanol which is much easier to diffuse through the gills.
What is even more interesting is that these double proteins occur due to a genome duplication event. The first set of genomes performs the regular daily activities in the body. This allows the secondary genomes to mutate into something useful like they did in the Goldfish. So, genome duplication was responsible for most of the species we see now adapting to new environments and circumstances.
Alexandra grew up dreaming of being a great science explorer. She always wanted to travel the world and explore some of the greatest science mysteries of the times. After high school, she studied chemistry in college and spent most of her summers working on research projects alongside her professors. It was there that Alexandra got clarity about what she wanted to do in the future. She now works full time in science research at a teaching university and is planning to go to medical school in a few years. She likes to stay up-to-date with the latest discoveries in science and share her love for science through her writing.