Speaker 1: Welcome to brain stuff from how stuff works. Hey, brain stuff,
Speaker 1: it's Christian Seger. Goldfish don't need teeny tiny moonshine stills.
Speaker 1: These little guys they can actually handle homebrewing all by themselves,
Speaker 1: as evidenced by the findings of a recent study published
Speaker 1: in the journal Scientific Reports. Although they don't distill whiskey,
Speaker 1: Goldfish have long been known for their ability to make
Speaker 1: their own alcohol. Until now, though, scientists have puzzled over
Speaker 1: how they manage this phenomenon. So why would a fish
Speaker 1: need to make alcohol? The ability is seen in both
Speaker 1: goldfish and it's wild relative, the Crucian carp Both are
Speaker 1: from the genus Kara sous, which often live in conditions
Speaker 1: that would be completely unthinkable for other species. Typically, a
Speaker 1: vertebrate can only survive minutes without oxygen, but these species
Speaker 1: have evolved to the point where they can last four
Speaker 1: or five months in oxygen deprived environments like the bottoms
Speaker 1: of rivers, frozen lakes, and even your poorly cleaned aquarium
Speaker 1: at home. When a creature is left without oxygen, it
Speaker 1: typically experiences a build up of lactic acid, which can
Speaker 1: turn toxic. However, these particular fish have two sets of
Speaker 1: proteins in their muscles rather than the usual one. The
Speaker 1: second set of proteins get activated when there isn't any
Speaker 1: oxygen and changes lactic acid into ethanol. This biochemical adaptation
Speaker 1: allows the fish to diffuse the substance into the water,
Speaker 1: helping them prevent the life threatening condition lactic acidosis. Now
Speaker 1: on fizz dot org, University of Liverpool evolutionary biologists Michael
Speaker 1: Baron Brinck explains how these fish pull it off during
Speaker 1: their time in oxygen free water in ice covered ponds,
Speaker 1: which can last for several months in their Northern European habitat.
Speaker 1: Blood alcohol concentrations in Crucian carp can reach more than
Speaker 1: fifty milligrams per one hundred millilders, which is above the
Speaker 1: drink and drive limit in these countries. However, this is
Speaker 1: still a much better situation than filling up with lactic acid,
Speaker 1: which is the metabolic end product for other vertebrates, including humans,
Speaker 1: when devoid of oxygen. Now, this ability has turned these
Speaker 1: species of fish into quite the Darwinian geniuses in the study.
Speaker 1: The research explains that the evolution of the ethanol producing
Speaker 1: pathway has not only made the goldfish one of the
Speaker 1: most arguably resilient pets under human care, but has also
Speaker 1: clearly provided Karasus with unique ecological benefits, allowing survival in
Speaker 1: waters that are unin habitable for other fish, thereby evading
Speaker 1: pisicene predation and interspecific competition. And check this out. The
Speaker 1: mad skills of the Crucian carp don't end with alcohol production.
Speaker 1: Historical accounts claim that they can survive several hours out
Speaker 1: of water, or even several days with a frozen outer layer.
Speaker 1: Today's episode was written by A. Leah Hoyt and produced
Speaker 1: by Dylan fig. For more on this and other topics,
Speaker 1: please visit us at house to works dot com