Goldfish brew booze to stay alive in freezing winter water

Animals, like humans, can't live without oxygen — our cells need it in order to suck the most energy out of sugary glucose molecules. When we exercise, panting for more oxygen, we cut corners and only break down glucose a little bit, to a chemical called pyruvate. But that means producing lactic acid and storing it in our muscles until we have enough oxygen to deal with it. It can give us a little wiggle room on the oxygen front, but it's hardly a perfect system.

Some bacteria have a different trick for dealing with a shortage of oxygen: They can break down glucose into pyruvate, then convert that compound into either lactic acid or ethanol and ship it out of their cell. We've taken advantage of that trick for millennia: When we humans are around, we set them up so that lactic acid or ethanol ends up in yogurt or booze. The definition of fermentation isn't actually producing alcohol, it's this process of breaking down glucose without any oxygen around.

And scientists just announced the first known group of animals that can get by on fermentation alone for long periods of time in an article published in Scientific Reports.

Scroll through to see an incredible art exhibit:

15 PHOTOS
Goldfish art exhibit
See Gallery
Goldfish art exhibit
Installations using goldfish in illuminated tanks are displayed at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
A staff member works to prepare the Art Aquarium exhibition in Tokyo, Japan July 5, 2017. Picture taken July 5, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
Staff put plastic bag holding fish into tanks as they prepare the Art Aquarium exhibition in Tokyo, Japan July 5, 2017. Picture taken July 5, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
Hoses fill a tank with water prior to the Art Aquarium exhibition in Tokyo, Japan July 5, 2017. Picture taken July 5, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
Women wearing traditional costumes take a look at installations using fish in illuminated tanks at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
Installations using goldfish in illuminated tanks are displayed at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon TPX IMAGES OF THE DAY
Installations using goldfish in illuminated bowls are displayed at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon TPX IMAGES OF THE DAY
A man looks at an installation that uses goldfish in illuminated bowls at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
Women wearing traditional costumes take a look at installations using fish in illuminated tanks at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
Staff work to prepare the Art Aquarium exhibition in Tokyo, Japan July 5, 2017. Picture taken on July 5, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
A woman wearing a traditional costume takes a look at installations using fish in illuminated tanks at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
Japanese Art Aquarium artist Hidetomo Kimura puts goldfish in a tank as he prepares the Art Aquarium exhibition in Tokyo, Japan July 5, 2017. Picture taken July 5, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
Goldfish swim in illuminated tanks at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon
A woman looks at an installation that uses goldfish in an illuminated tank at the Art Aquarium exhibition in Tokyo, Japan July 6, 2017. About 5,000 goldfish and 3,000 tropical fish are displayed in 130 uniquely shaped tanks. This unique art form uses fish along with LED lights, projection mapping and music in a show produced by Japanese Art Aquarium artist Hidetomo Kimura. REUTERS/Kim Kyung-Hoon TPX IMAGES OF THE DAY
HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

It's the humble goldfish and its wild relatives, certain species of carp.

The fish in this genus — called Carassius — that haven't managed to score a comfortable life indoors have it pretty rough. They spend their lives in lakes in Europe and Asia — but those lakes tend to freeze over in the winter. That leaves crucian carp and goldfish to spend four or five months in water with little or no oxygen.

A team of primarily Norwegian biomedical researchers wanted to learn how the fish were surviving.

Scientists had already figured out that the fish were creating ethanol and essentially breathing it out through their gills into the water around them. But the researchers on the new study wanted to pin down exactly what cellular machinery the fish had to accomplish the feat.

So they caught a bunch of crucian carp, put them in tanks that either contained or lacked oxygen, and let them swim around a while. Then they killed the fish and ran a series of tests to see what genes were activated and what proteins were common in the oxygen-deprived fish compared to normal fish.

They found a perfect pair: two different variants of an enzyme called E1, which handles the first step in breaking down pyruvate. One version looked just like any other animal's — but one version was a little different, and awfully like the version in yeast, our favorite beer-brewer.

When there isn't much oxygen around, the fish just switch to the yeast-like enzyme and keep chugging along.

The team was also able to trace the origins of the enzyme pair back about 8 million years, when the genome of the fish's ancestors managed to duplicate itself, giving evolution the space to play with one copy of the enzyme's instruction manual.

Related: Spooky underwater spots

12 PHOTOS
11 hauntingly beautiful underwater sites
See Gallery
11 hauntingly beautiful underwater sites

Yonaguni Monument, Japan

The Yonaguni Monument was discovered in 1986 off the coast of Yonaguni, one of the Ryukyu Islands in Japan. Since then, it has been the subject of much speculation and debate. The rock formation has tiered planes and straight edges, giving it a sort of pyramid shape. While some think the shape looks manmade, others claim the stratigraphy is normal for sandstones in areas with tectonic activity. So: Japanese Atlantis or geological wonder? Therein lies the monument's mystery—and appeal.

Photo: Getty

Museo Subacuático de Arte (MUSA), Cancun, Mexico

This enchanting underwater museum features more than 400 permanent life-size sculptures on the ocean floor, each designed to promote coral and marine life. Visitors reach the museum via boat and snorkel above the statues, which range from groups of people to a Volkswagen coated with seaweed.

Photo: Getty

Ginnie Springs, Florida

Florida has a wealth of freshwater underwater caves to explore, but Ginnie Springs stands apart for its accessibility and crystal-clear water. There’s no need for extra training to explore the large cavern in Ginnie Springs; it’s been deemed safe enough for open-water certified scuba divers to enter. The upper portion is lit by sunshine filtering through the entrance—an impressive sight. —Jonathan Shannon

Photo: Getty

Shipwreck of the Sweepstakes, Lake Huron, Ontario, Canada

There are over 6,000 shipwrecks in the Great Lakes, most of which have not been accessed by people. But there are some wrecks visible in shallower waters, including the schooner Sweepstakes, located in Lake Huron's Big Tub Harbour in Fathom Five National Marine Park. The boat sank about 50 yards from the shore in September 1885 and has remained surprisingly intact ever since, making it a popular attraction for divers and tourists.

Photo: Getty

Dos Ojos, Tulum, Mexico

This cavernous cenote with double entry points—hence the moniker "Two Eyes"—is so incredible it was featured in the IMAX film Journey Into Amazing Caves and an episode of Discovery Channel's Planet Earth. It's perfect for snorkelers, experienced scuba divers, and daredevils willing to surface in the system's bat cave.

Photo: Gallery Stock

Christ of the Abyss, San Fruttuoso, Italy

The eight-foot-tall Christ of the Abyss is located in the Mediterranean Sea off the coast of San Fruttuoso, where it has stood waiting for divers since the 1950s. With its outreached arms and upward gaze, it's hard to decide whether the statue is sublime or spooky. Regardless, it's worth taking a 55-foot dive down to snap an underwater selfie with Jesus.

Photo: Alamy

Christ of the Abyss, Key Largo

There are several versions of the Christ of the Abyss statue scattered around the ocean floor, including a famous one in Key Largo. The Floridian replica is a bit more accessible at a depth of 25 feet, but the effect is haunting all the same.

Photo: Getty

Great Blue Hole, Belize

The Great Blue Hole is a 1,000-foot-wide, perfectly circular sinkhole in the middle of Belize's Lighthouse Reef, as well as a famous spot for divers. The limestone shelf surrounding the vertical cave sits about 40 feet below the surface, and then it’s a straight jump down into the unknown. The further down divers go, the clearer and more beautiful the massive underwater stalactites and stalagmites become.

Photo: Alamy

The Green Lake, Tragoess, Austria

During the fall and winter, Austria’s Green Lake is a small but scenic body of water surrounded by popular hiking trails. But when the snow on the bordering mountains begins to melt in the spring, the runoff causes the lake’s water levels to rise. By June, the nearby park becomes completely submerged, making for one of the most unusual diving experiences in the world.

Photo: Alamy

Silfra fissure, Thingvellir National Park, Iceland

Iceland's Silfra fissure offers adventurers something that no other diving spot in the world can—the chance to swim between two continental plates. The crack between the Eurasian and North American plates widens about 2 cm each year, inviting divers and snorkelers to enjoy the impressive water visibility, bright green algae, and sheer geological uniqueness.

Photo: Getty

Amphitrite statue, Grand Cayman, Cayman Islands

If you ever want to come face-to-face with a mermaid, consider booking your next vacation to Grand Cayman. One of the island's quirkiest attractions is a ghostly mermaid statue sitting in 50 feet of water off the coast of the beach, where she has been chilling since 2000. The 9-foot-tall, 600-pound sculpture is based off of Amphitrite, goddess of the sea and wife of Poseidon in Greek mythology.

Photo: Getty

HIDE CAPTION
SHOW CAPTION
of
SEE ALL
BACK TO SLIDE

But there's a strange side effect. Since the alcohol the fish produce diffuses out into the water passively, there are still high levels inside the fish. According to one of the study's authors, their blood-alcohol content during the winter oxygen shortage is actually, incredibly, over the legal limit for driving in the countries where the fish live.

Fortunately, no one's ticketing them for swimming drunk.

Read Full Story

Sign up for the Best Bites by AOL newsletter to get the most delicious recipes and hottest food trends delivered straight to your inbox every day.

Subscribe to our other newsletters

Emails may offer personalized content or ads. Learn more. You may unsubscribe any time.