Monday, September 04, 2017 by Rhonda Johansson
Goldfish fill their bodies with alcohol to survive for days (even months) in oxygen-free frozen water. Evolutionary physiologists say that they have now discovered the mechanism in which the fish — and their wild relatives, the crucian carp — are able to live in an environment where most vertebrate animals would die within minutes.
Typically, in an anaerobic environment, animals overproduce the compound lactic acid. The lactic acid is meant to be utilized for energy production. However, when there is a persistent oxygen deprivation, an organism can die from lactic acidosis.
Goldfish are able to convert the lactic acid into ethanol. The alcohol by-product then diffuses across the fish’s gills into the surrounding water. While the fish remains rather sedentary during this time, the animal is not encumbered by a dangerous buildup of lactic acid in the body. Scientists say that the fish could be “a little tipsy” at this time, which may explain why the fish prefer to remain as immobile as possible in their tiny space.
The results of this study were published in Scientific Reports.
The molecular mechanism involved in this intriguing processing can be found in a protein set produced by the muscles of the goldfish. Strikingly, goldfish and crucian carp carry two sets of a specific protein. While one is normally seen in other species, the second set is only activated by the absence of oxygen. It is a mutation found in the species which biologists say is the evolutionary response of its ancestor some eight million years ago.
The mutation prompted the production of ethanol and allowed it to be channeled outside the mitochondria. This allowed the goldfish to stay in an area where little to no predators could survive.
It also had the expected result of making the fish a tad drunk.
As explained by Dr. Michael Berenbrink, one of the authors of the study, “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 50 mg per 100 millilitres, which is above the drink-drive limit in these countries.”
“However, this is still a much better situation than filling up with lactic acid, which is the metabolic end product for other vertebrates, including humans, when devoid of oxygen,” he further added.
This is a fun study to read, and can trigger a bunch of hilarious jokes and puns. Nevertheless, this is not, in any way, a recommendation to inebriate yourself during winter. Remember that you are not a goldfish and do not contain the protein set which converts lactic acid into ethanol. Evolutionary biologists say that their study provides answers to how certain animal species have adapted for survival. It may also explain why goldfish remain one of the more resilient pets to date.
Always consider that alcohol is a socially-accepted drug and should only be consumed in moderation. Responsible drinking is always the better choice. Take note that vision, coordination, and even rational thinking can be affected by drinking. This is why there are legal drink-driving limits which are based on one’s blood alcohol concentration (BAC).
BAC is measured through a breathalyzer or blood sample. The U.S. limit for driving is a score of .08, which means that a person has .08 grams of alcohol for every 100 mL of blood.
Several factors can affect BAC including: the type of alcohol you were drinking, the percentage of alcohol in the drink, individual differences in height, weight, and metabolism and if you were drinking quickly, among other things.
Medical science which proves the benefits of alcohol are conflicting. To err on the side of caution, people are recommended to just drink water instead. (Related: Can Alcohol REALLY Benefit Your Health?)
There are no studies which empirically prove alcohol’s use in surviving harsh weather conditions in humans.
Read more stories like this on Research.news.