Goldfish lifespans are often thought of as very short, just like many other fish. Perhaps your first fantail goldfish purchased at a local carnival died in just a week. Or a fancy goldfish you bought a nice small bowl for only lived for a few years. But is that really the average lifespan of a common goldfish?
As it turns out, goldfish can live for a very, very long time. In fact, a goldfish may outlive you if you care for it well enough! So how long do goldfish live, anyway? What affects their lives, and how can I increase the lifespan of my pet goldfish?
How Long Do Goldfish Live?
Like all aquarium fish, the average lifespan of a goldfish varies mostly due to environmental factors. Food quality, food amounts, water quality, temperatures, diseases, tank mates, and more can affect goldfish lifespan. That said, there are some major differences in goldfish lifespan that depends on the variety…
Common Goldfish Versus Fancy Goldfish
Even if you provide proper care for your pets, common goldfish tend to outlive fancy goldfish. This is mostly due to their more diverse genetic heritage. Thanks to selective breeding, fancy goldfish like ranchus, telescope eyes, and oranda goldfish tend to live from 10 to 15 years. Fancy goldfish lifespan is still very impressive compared to guppies, which live only 1 to 3 years even if given proper care.
But common and comet goldfish are the record setters for how long goldfish live! According to Guinness World Records, the oldest goldfish was Tish, who won at a local fair in 1956. Tish lived for 43 years! Comets are simply long-finned common goldfish and have none of the selective breeding that shortens a fancy goldfish’s lifespan.
Feeder goldfish are also worth talking about. While they are also common and comet goldfish, these fish rarely live a healthy life. Feeder goldfish are kept crowded next to sick fish in tanks with high ammonia levels. Their immune systems are constantly being assaulted by bacteria and parasites as well – and 99% of them end up as food for other animals. But genetically speaking, nothing is preventing them from having long lifespans like their non-feeder cousins. If you decide to rescue a feeder goldfish, you may find that it, too, lives to a ripe old age of 30-40 years!
Wild Carp and Koi Lifespans
As impressive as Tish’s lifespan was, wild carp and koi can live as long or even longer! The European Common Carp have been known to live around 38 years of age. Being close relatives of the Asian Carp that Goldfish are descended from, it’s not surprising that common and comet goldfish are so long-lived.
Koi are another close relative that takes longevity to a whole new level! Instead of keeping them in a tank, the vast majority of koi are kept in outdoor ponds, making a big difference. Seasonal variations in temperature and water chemistry stimulate their immune system. They have the chance to hibernate each year. And an abundant supply of algae, insects, and other natural fare supplements their diets.
Koi are especially long-lived in Japan, where they were first domesticated. On average, Koi will reach 40 to 60 years of age. But there are several examples of Koi that lived to be 100 years old – and the oldest known Koi was Hanako (“flower girl” in Japanese), who was verified upon her death as being 226 years of age! She also weighed 16.5 lbs and was nearly 28 inches in length.
The Longest Living Fish of All
Goldfish and Koi have impressive lifespans for fish. But what about other fish, both freshwater and saltwater? The Bigmouth Buffalo (Ictiobus cyprinellus) is a North American carp relative that regularly lives up to 80 years and can exceed 110 years in age.
Saltwater fish are even more impressive when it comes to life expectancy; the oldest Rougheye Rockfish was dated 205 years of age. And the oldest known Greenland Shark, a prehistoric-looking polar fish, was 392 years, plus or minus 120 years. Scientists also estimate that they actually take 150 years just to be old enough to breed!
How Can I Ensure My Goldfish Have a Long Lifespan?
Goldfish lifespans are dependent not only on their breed but environmental factors as well. Let’s take a closer look at what these factors are.
Goldfish Health Problems
One way to identify goldfish health problems is to study their body shape. Round bodies are one of the best indicators of good health. While some goldfish, such as fancy orandas and ranchus, tend to be especially plump, even common goldfish should be nice and stout if well fed. Round bodies are also a sexual indicator, with females being noticeably rounder than males even when not in breeding conditions.
Slim-bodied goldfish are sometimes just naturally trim. But a slim profile can also indicate a lack of regular or good quality goldfish food. Goldfish suffering from parasitic infections like intestinal worms may not be getting enough nutrition and remain skinny despite eating frequently.
What Is the Correct Diet for Goldfish?
To improve fish lives, we need to offer a diet that goes beyond prepared formulations. Most goldfish enjoy variety in their diet. This means pairing your high-quality flake or pellet regime with live and frozen foods, similar to what they’d find in nature.
Notice how your fish spend a lot of time rooting along the bottom of your tank or pond. In their natural habitat, they would dig up small worms, clams, snails, shrimp, and other hidden goodies to go along with their diet of soft aquatic plants. Goldfish are known as “omnivores,” meaning they eat both plants and animals, just like humans.
That’s why offering them brine shrimp, tubifex worms, water fleas, bloodworms, small snails, chopped shrimp, and other invertebrate-based delicacies is one of the best ways you can increase their life expectancy!
And like I mentioned before, vegetable matter is also important for goldfish because it provides them with both roughage and necessary vitamins missing from conventional formulas. Spirulina algae flakes, algae wafers, and even bunches of soft plants like Anacharis and Cabomba form a salad buffet your goldfish will love you for!
Outdoor Ponds Versus An Indoor Aquarium for Goldfish
When keeping goldfish alive, you have the choice of keeping them in outdoor ponds or an indoor tank. Actually, some goldfish keepers rotate their fish year-round, keeping them outdoors when there is warm water in the summer and moving them indoors for the winter.
Many of the longest-lived goldfish tend to thrive outdoors. The constant low-level stimulation that occurs as the seasons influence the water temperature strengthens the immune system. They can bathe under natural light, graze on algae and aquatic plants, and they can find mosquito larvae, small snails, and other delicacies, just like their natural environment would normally provide. Ponds are large enough to easily include other goldfish as well. Other fish offer social stimulation that encourages them to display, spawn, and improve their quality of life.
So long as you keep them in a large tank with good water quality, your goldfish lifespan should not decrease much, if at all. A varied diet also helps with their average lifespan. Plants consume ammonia, nitrite, and nitrate while releasing oxygen, which is very important for aquatic life. But a power or canister filter, alongside an aerator, simulates the same process using technology. Just remember that bowls, with their cramped, still water and lack of filtration, won’t allow goldfish to survive for long.
Keeping Fancy Goldfish In Ponds Versus Tanks
Fancy goldfish breeds are the exception here. Fancy goldfish tend to prefer warm, even tropical water, as they have been mostly bred indoors for generations. A few Japanese breeds, such as the Wakin and Tosakin, were bred for pond life. Japanese goldfish (and koi) are bred for top viewing pleasure since that’s how you see fish when standing next to a pond. But many other goldfish varieties, such as telescope eyes and orandas, were bred to be viewed from the side, as in an indoor aquarium.
Fancy goldfish don’t do well with the temperature extremes of outdoor ponds and may not survive a full overwintering the way hardier varieties can. Common, comet, shubunkins, and other outdoor breeds will lower their metabolisms as winter approaches. Remember, China and Japan are mostly temperate countries, just like the United States, so snow and ice visit each year.
Once your pond freezes over, assuming it’s at least 3 to 4 feet in depth and has enough water volume (or air holes) to provide oxygen, goldfish, and koi enter a state of suspended animation. But fancy goldfish don’t reliably enter this state as they haven’t had to do so for many, many generations. It’s better to pamper them with a stable indoor room or tropical water temperatures year-round!
Give Your Goldfish Space!
Space is another ingredient that you can use to maximize goldfish lifespan. There’s a myth that just won’t die surrounding goldfish care. People often ask me, “do goldfish only grow to the size of their environment?” And the answer is a resounding “no, they do not!” Goldfish will grow as large as their food, genetics, and other conditions allow for. A tiny environment can stunt their growth to a degree, but that’s kind of like keeping a puppy in a box its entire life.
Since we want our fish to be active, healthy, and not just surviving but thriving, we should provide our fish with all of the room they need as they grow. Most fancy goldfish reach 5-8 inches at maturity, though it’s possible for them to grow a few inches larger over the years as well. Therefore you should be keeping a single fancy goldfish in at least a 20-gallon tank, with 10 additional gallons of space per extra adult goldfish.
Common, comet, shubunkins, and other goldfish closer to wild carp will reach anywhere from 8-14 inches in length. There is even a Japanese bred Giant Goldfish variety that reliably tops 20 inches! Therefore as adult goldfish, we want to provide them with at least a 55-gallon tank, with an outdoor pond being even better for them! That said, you can certainly keep a 1 to 2-inch baby goldfish in a 5 or 10-gallon aquarium for a while. Just remember that it will grow over time, and it will eventually need an upgrade in living quarters!
Goldfish Water Quality
How much space you provide your goldfish also influences the water quality of the tank or pond, which influences how long they live. The more fish you have, the more ammonia and other waste products tend to accumulate. This increases the load on your filter to keep up.
And if you aren’t performing enough water changes to remove the excess, you’ll definitely decrease the lifespan of your goldfish. A filter for your goldfish goes a long way.
Even low levels of ammonia, nitrite, and nitrate are constant irritants that are normally undetectable in nature. Use an aquarium water testing kit to check your water.
Goldfish are super hardy, and low detectable levels of these chemicals are unlikely to kill them. But a constant amount will cause them problems that shorten their lives.
We covered quite a bit of ground in this article! As it turns out, there’s a lot more to the question, “how long do goldfish live.” People usually think it all comes down to breed. And to be fair, genetics do play a major role. Fancy goldfish simply don’t live as long as less selectively bred varieties. But you can definitely increase the lifespan of your goldfish by offering a wide variety of live, fresh, and frozen foods alongside their prepared food diet.
Keeping track of your goldfish’s water quality regularly will ensure ammonia and other toxic agents don’t accumulate, shortening their lives. Like with any pet, a clean environment prevents most problems from ever occurring. And if you can (assuming you have a hardier breed), keeping your goldfish in an outdoor pond provides them with all of the space they need, plus a buffet of invertebrates and algae to munch on!