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People have been raising goldfish for centuries, but they haven’t always done so in ways that maximize their pets’ lifespans. Goldfish have a reputation for being delicate and short-lived, but that’s likely because they are commonly kept in bowls and other cramped quarters. Because of those tight conditions and the likely poor water quality that results, these fish may only live a few weeks or months, whereas if they were kept in better conditions, they could happily live for many, many years.

In the wild, goldfish typically live between 6–7 years, but with proper care and suitable habitat (such as a well-maintained pond or aquarium), some varieties may live as long as 25 years. In-fact, goldfish have the potential to live even longer than that — for example, the oldest goldfish on record lived to be 45 years of age!

Most common goldfish varieties are also extremely hardy, able to tolerate water temperatures between 32-10°F (5 0–41 °C), very muddy or opaque water, and low levels of dissolved oxygen (though these conditions are far from optimal in terms of lifespan).

When do Goldfish Spawn, Lay Eggs & Mature?

Goldfish breed readily and grow quickly. Eggs hatch within 4 days, producing small, hair-like juveniles called “fry.” Fry should be isolated when they’re first hatched, but after a month they can be moved to a pond. Goldfish start life with the same gray-green coloring as their wild counterparts. While a few never change color, most develop their distinctive hue, as well as patterns and other features such as hoods, between the ages of 5 and 12 months.

Goldfish are commonly said to reach sexual maturity after one year, though research has indicated they may be ready to reproduce as early as 225 to 233 days old. Younger adult goldfish tend to produce smaller, less viable eggs, while older individuals may be more likely to lay infertile eggs. For this reason, goldfish are considered in sexual prime when they’re between the ages of 2 and 4.

Do All Goldfish Breeds Have the Same Lifespan? How Long Do Fancy Goldfish Live?

Because of their varied anatomies, different breeds of fancy goldfish may have shorter life expectancies than common goldfish. Comets, Shubukins, and Fantails, which share many of the same traits as common goldfish, tend to have similar lifespans. “Fancier” breeds with more distinctive, unnatural features, such as Bubble Eyes and Lionheads, tend to live a considerably shorter 6-8 years, though they may reach a maximum age of around 15 years.

The difference in lifespans between fancy and common goldfish can be explained by a couple of factors. Fancier goldfish are generally more delicate than common goldfish and especially more sensitive to water pollution. Smaller imperfections in water quality and environmental changes are more likely to adversely affect their lifespans.

Furthermore, many of the physical traits that fancy goldfish are bred for can negatively impact their quality of life and therefore their life expectancies. Goldfish with round, egg-shaped bodies, such as Ranchus, Pearlscales, and Orandas, are more prone to swim bladder/buoyancy problems because their swim bladders (the organs that control buoyancy) are unnaturally shaped, meaning that they tend to retain too much air. This is especially problematic because many fancy goldfish aren’t very efficient swimmers to begin with. Their spherical bodies are difficult to control, and many lack dorsal fins or have impractical tails, making it harder to get away from predators and compete for food. This also may make them targets of nipping or bullying from other fish, as well as put them at higher risk of conditions like fin rot.

The hoods of breeds like Orandas, Lionheads, and Ranchus often develop bacterial and fungal infections and may grow large enough to obscure eyesight. Perhaps most obviously, the unusual eye formations of breeds like Celestials, Globe Eyes, and Bubble Eyes frequently impair vision and are prone to injury and potentially fatal infections.

With respect to other species of carp, highly specialized fancy goldfish can still have long lifespans if their unique vulnerabilities are factored into daily care and pond up-keep.

How to Improve the Lifespan of Goldfish (Tips for Healthy Pond Goldies) 1) Maintain Good Water Quality

Monitoring water quality using a water test kit is crucial for maintaining good water conditions. Even hardy non-fancy goldfish are particularly intolerant of nitrogen compounds like ammonia, nitrate, and nitrite; in a perfect pond, levels of all 3 would be as close to zero as possible!

Understanding where these harmful compounds come from can help prevent them from building up. Nitrogen compounds are often found in fertilizers and pesticides; avoid using these substances near ponds. Ponds should also be built on elevated surfaces or in some other way blocked from rainwater run-off, as water flowing in can carry pesticides and fertilizers along for the ride.

Decaying organic matter is another significant source of ammonia problems, especially in heavily planted ponds. Dead plants produce ammonia as they rot and should be removed as quickly as possible. Live plants, however, use up nitrogen compounds to make food, meaning that some plants actually benefit goldfish more than by just being something to nibble! Oxygenating plants are a great addition to ponds to provide both oxygen and a underwater cleaning service.

Rotting fish waste and uneaten food also produce ammonia, nitrites and nitrates that can shorten a goldfish’s lifespan. To limit these issues, avoid overfeeding your fish, only feed high quality foods, and invest in a quality filtration system comprising both mechanical and biological components.

Goldfish also need plenty of oxygen to live long lives. The same strategies that limit nitrogen compound buildup can also optimize a pond’s dissolved oxygen levels. Not overstocking ensures plenty of oxygen to go around. Decaying organic matter, such as rotting feces, uneaten food, and dead plants, consume oxygen, though live plants produce it and should be encouraged. Maximizing pond surface area and installing aeration devices such as fountains, bubblers, and air pumps can help as much oxygen as possible incorporate into the water. These devices will not only help oxygen the water directly, but also provide additional aeration to the surface waters, preventing stagnation, which can encourage bad bacteria, mosquitoes, and algae growth.

Maintaining adequate water temperature and pH levels can promote long life in goldfish. Ideally, goldfish ponds should have water temperatures between 20–25 °C and receive about 6–10 hours of direct sunlight per day. The optimal pH range is 7–8, though anything between 6.6–8.5 is okay. Measure ammoina levels, dissolved oxygen, and pH levels, as well as water temperature, at least once a month at approximately the same time of day (as these can vary over 24 hour period).

Similar to koi, common goldfish are well adapted to survive winters in frozen ponds if necessary, but you should still take the time to clean the pond before it freezes over, as well as providing oxygenation through a hole in the ice once it freezes. Preparing the pond for winter is called “winterization”, which you can read more about here!

Unlike common goldfish, most fancy goldfish breeds cannot survive outdoors in the winter and must always be brought indoors when things get too chilly. Even in very deep ponds where warmer water collects towards the bottom, conditions may still be too cold for some fancy breeds.

Goldfish are omnivores; in the wild, they mostly eat plants and insects, as well as smaller fish and crustaceans like daphnia. Goldfish lifespan can be improved with a routine that reflects this natural diet through a mix of packaged and fresh food. When it comes to pellet feeds, look for brands that blend high quality aquaculture protein and vegetable matter and that list protein as the highest percentage ingredient. If you select a extremely high quality feed, it should provide almost all nutrition a goldfish needs to live a healthy life.

As treats, or for additional nutrition, live and/or fresh foods are often more nutrient dense and better digested than dry food and gels, allowing fish to grow a little faster and achieve more vivid colors and patterns. Goldfish tend to eat more greens than other fish, and common vegetables like spinach, green peas (shelled), and broccoli, as well as aquatic plants such as duckweed and elodea, are all highly beneficial. Regarding other animals, daphnia and brine shrimp are particularly nutritious and high in protein, though bloodworms, earthworms, and mosquito larvae are also good choices. If obtaining live or fresh food is difficult, frozen or freeze-dried versions can be substituted (though always pre-soak freeze-dried foods to prevent bloating or constipation).

Even when kept in backyards, goldfish are still vulnerable to predators. Adult goldfish face the most danger from herons, cats, birds, and racoons, though smaller garden creatures such as frogs and salamanders also pose threats. High, tight fences can help somewhat but rarely stop birds or racoons. The best tools for protecting adult goldfish are leaf nets or other tight-fitting covers. Motion-sensitive sprinkler systems may also deter predators, as well as man-made fish shelters so your fish can hide away safely when there is a threat.

Fry are primarily threatened by adult goldfish and should therefore be separated for at least the first few weeks of life. Their small size also puts them at risk from insects like diving beetles and water boatmen. If kept outside, protect fry for about the first 4 weeks of life by covering their habitats with a tight, fine mesh. After 4 weeks, the fry should be large enough that insects no longer pose any danger.