As you see a goldfish pond in the summer, your thoughts might turn to how those beautiful creatures survive in winter under a sheet of ice. Well, a group of scientists with the University of Liverpool in the United Kingdom believes that they have discovered what helps keep them and some of their relatives alive. It appears that some fish make alcohol while they are in wait for oxygen. Also, for a few them, that blood alcohol level can rise over the legal limit to drive in most countries.
Some Fish Include Goldfish and the Carp
When ice covers a pond or lake during winter, the oxygen levels can drop quickly depending on how much water volume there is. It also depends on how many creatures live within this body of water using up its oxygen reserve. This can spell death for some fish during an unusually long or harsh cold season.
The bodies of fish and most other animal species produce a substance called lactic acid whenever oxygen levels run low in the bloodstream. Lactic acid is toxic, and it is the same stuff that causes the muscles to feel sore after a hard workout.
Well, it seems that goldfish and their cousins in the carp family have developed a secondary system that kicks in inside their cells when their oxygen levels run low. This causes the cellular mitochondria to make alcohol out of the lactic acid in a process not that different from fermentation.
“The ethanol production allows the crucian carp to be the only fish species surviving and exploiting these harsh environments,” claimed Dr. Cathrine Fagernes, “thereby avoiding competition and escaping predation by other fish species with which they normally interact in better-oxygenated waters.”
Fagernes is the study author and also part of the University of Oslo, which also participated in the study. She then went to point out that this adaptation may be one of the reasons why the goldfish, the ‘carp’s cousin’, ‘is arguably one of the most resilient pets under human care.”
Study results and further details are available in the journal Scientific Reports.
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