Can You Freeze Goldfish?

[PistolPete]

So if fish can survive being frozen for the wiinter why do lakes have winterfkill if they freeze to the bottom and kill all the fish. I know winterkill removes the oxygen in the water butg a frozen fish needs no oxygen. And when a lake gets winterkill it is wiped out.

[jvision]

Well, since not every lake that freezes solid gets completely wiped out, I'd have to imagine it could do with the speed at which the freezing happens, possibly resulting in ruptured organs?

[DanGofCalgary]

So if fish can survive being frozen for the wiinter why do lakes have winterfkill if they freeze to the bottom and kill all the fish. I know winterkill removes the oxygen in the water butg a frozen fish needs no oxygen. And when a lake gets winterkill it is wiped out.

not all species of fish maybe? And even within a species maybe not all the fish survive? and maybe it freezes for longer than they can recover?

Just guessing though. I really don't know for certain. I have however experienced what Jorg described of fish recovering after being out on the ice all day. Maybe they don't recover completely though. Maybe they are 'alive' but would die shortly thereafer? Still just guessing.

[Nauticus]

There are many animals that do freeze all winter and reanimate in the spring. However the conditions need to be natural and somewhat perfect. Remember that in nature freezing almost never occurs underwater to the extent in temperature as it does in your freezer at home. Most frozen lakes rarely reach temperatures lower than -10 C and that is much colder than any oceanic freezing temperatures. Furthermore, most animals have a slow and gradual process to prepare for freezing as the Earth is rarely lifted out of orbit and thrust into a sun shielded container with some hefty icepacks, a bucket of ice cream and peas.

Some organisms even have separate types of blood cells specially designed to coat organs in their body and protecting them from "freezer burn" by preserving glucose and moisture levels to more like a slush rather than allowing harmful ice crystals to tear and lacerate the soft tissues.

Here are some links and an article on the biology of the process to better explain this wonderful and somewhat magical process.

"The animal most often quoted as surviving freezing is the wood frog. I have combined information from a number of websites about this very unusual animal.

http://www.arcticblast.polarhusky.com/frozenfrogs http://www.pbs.org/safarchive/3_ask/archive/qna/3274_j-n-kstorey.html, http://seattletimes.nwsource.com/html/nationworld/2002118796_frogs14.html and http://www.bwca.cc/wildlife/copingwithwinter.htm state that the wood frog has expanded its range to Alaska, Yukon and the Northwest Territories. It survives the ferocious winters by freezing alive. It can survive at temperatures down to -6°C, as this is the lowest temperature it encounters in its habitat, when it is under a thick layer of leaves or under rotting logs or in crevices around tree roots, under a blanket of snow. A frog will not survive if frozen in a home freezer at -15°C. It takes a long time for a frog to freeze. This enables it to initiate adaptations that protect it in the frozen state.

Before winter comes, the frogs eat ravenously, storing a starch in their livers. During the winter, the frog saves a huge stockpile of carbohydrate in its liver as glycogen. It used this when it had to quickly raise its blood sugar levels for cryoprotection (staying alive while frozen). A freeze triggers their bodies to convert the starch into other compounds, most often glucose, or blood sugar or glycerol. The frogs become, in essence, diabetic. Ice crystals begin forming just beneath the frog's skin, when the temperature drops below 0°C and the normally pliant and slimy frog becomes slushy. Stimulated by the freezing temperature, starch, which is stored in the liver, is converted into glucose (blood sugar) or glycerol. If, after 3 hours, the temperature falls lower, ice races inward through the frog's arteries and veins. The glucose is distributed to the major organs and muscles, lowering the freezing temperature of the water inside the frog's cells.

After 24 hours, the glucose or glycerol prevents the water inside the frog's cells from freezing, but allows ice to form in spaces around the cells and in the cavities around the organs. Some of the glucose may be used as a fuel to generate energy in cells, while they are surrounded by cells and cut off from fuels that would otherwise be delivered by blood. The glucose lowers the freezing temperature of water inside the frogs' cells, so the cells stay liquid, even as ice fills the space around them. If the water inside the cells froze, the jagged ice crystals would destroy everything inside, killing the frog.

The organs can also use their own supply of glycogen (the polysaccharide carbohydrate reserve) for this purpose. The organs are surrounded by a mass of ice keeping them cool, without damaging them. This enables the frog to hibernate without any body functions, which require energy. When glucose or glycogen are fermented without oxygen, lactic acid accumulates as the end product in tissues and lactate builds up slowly in the organs while the frog is frozen. Carbohydrate fermentation fuels the low metabolic rate in frozen animals. Glucose tends to stay stable during the freeze.

The heart, lungs and brain stop working, while the eyes freeze to a ghostly white. The frog has no heartbeat, does not breathe and will not bleed if cut. Up to 65% of the body water may freeze, as the cells are protected by a natural antifreeze. The frog is very compact and solid to the touch and makes a small thud when dropped, but it is not dead and is unharmed by the process. The legs may be tucked in under the body, so there are no body parts sticking out and vulnerable to breaking off. One frog turned almost purple with its limbs and head stuck in contorted positions. The frog may survive being frozen from 2 weeks to perhaps 2-3 months, although the temperature under the snow may rise above freezing point at times.

When a thaw comes in the late spring, the frog can melt back into its normal state over several hours, restart its heart and hop away, unscathed. The frog loses its tolerance of freezing quite rapidly over just a few weeks after emerging from hibernation in the spring. This is because it can no longer make the huge amounts of glycerol it needs to protect its cells during freezing. It uses up the glycogen and glucose for breeding, just after the snow melts. There are 2-3 nights of very noisy and energetic activity, that uses up a lot of its body fuel reserves and these cannot be replaced for a time as the weather in the early spring for the many of the insects eaten by the frogs. Some other protective strategies that aid freeze tolerance are turned off in the summer, such as making special nucleating proteins in the blood. These proteins aid freezing survival by helping to stimulate and direct ice formation within the blood vessels, probably moulding crystals to grow in the least harmful way."

[PistolPete]

I knew frogs could do it. Im more curious with fish

[Nauticus]

That's the ticket, the principle is very similar.

Even some mammals can do this.

The frogs are an extreme because they can handle it for much longer periods and more extreme conditions, however this does not exclude the other species from similar behaviour.

[Evolution]

Once the serious fluid within the fish's body cavity has been frozen solid, the fish dies. This would happen within 24 hrs in a closed off compartment at 1 degree blow zero, as the fish is unable to generate it's own body heat. All the examples above of fish reanimating after freezing are fish who didn't suffer the serious fluid being frozen.

That being said, goldfish are very bad to feed to other fish as they contain an enzyme that destroys B vitamins in the fish eating them. This creates a whole series of developmental problems and health problems within a short period of time.

Also, if your aro is healthy, you can go away for an entire month and it'll have likely not lost a once of weight and would be safer in his own tank without food for two weeks than moving him. Same with the goldfish. We now know a small goldfish can go 6 months without food and not parish.