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The Goldfish Gazette, Issue #097 Goldfish Lifespans
January 30, 2022

Goldfish Care Tips

A Free Monthly Resource For Goldfish Enthusiasts
January 2022
Issue #097

In This Issue
Goldfish Lifespans

Goldfish kept in good a environment and fed a varied nutritious diet throughout their lives should live a long life, 10 years at the very least, 15 to 20 years should be expected.

Yet some Goldfish kept in pristine conditions by experts are dying well short of that.

Goldfish lifespans

I covered this subject back in 2015 in issue 17 because most Goldfish die within 12 months of purchase, so, the focus was on extending Goldfish lives by stressing their basic care requirements.

Since that e-Zine, and talking to Goldfish owners around the world, I have made some interesting observations:

1. Asian sourced, well cared for fish are dying young

2. The longest living Goldfish are often the ones kept in small aquariums, fed sparingly, and, because of this, are usually stunted.

So, how is this possible?

The factors that usually determine how long a Goldfish lives are these:


Fully grown Goldfish are large aquarium fish by any standards, and generally, the larger the animal the longer it lives.


The rate an animal ages is built into its genetic blueprint at birth. However, most Goldfish never live long enough for it to be considered a cause of death.


The more developed varieties of Goldfish such as Celestials and Water Bubble Eyes have the most mutated genes, and this is believed to make them weaker.

Water Quality

I suspect owners of long-living fish have maintained good water quality throughout their fish’s lives.

Water Temperature

Goldfish are warm water fish, not tropical. Most Goldfish live in unheated aquariums and ponds, so when winter arrives with its lower temperatures, Goldfish go into a period of low activity or if temperatures are low enough hibernation.

Water temperature plays a large part in the lifespan of fish. The colder the water the longer they live.


The majority of commercially available foods for Goldfish are dry prepared flakes or pellets. These are often the only foods that have been fed to the majority of the longest-living Goldfish.


Generally, fish kept in ponds live the longest, fish kept in bowls the shortest.

Some of the longest living Goldfish haven’t been given large amounts of room, often quite the opposite.


Looking back at the factors we thought determined how long a Goldfish will live, we can dismiss some and identify others that appear consistent.

Size – This can be dismissed as a factor because the longest living fish are often stunted and have never reached anything like their size potential.

Genetics – Goldfish sourced from tropical Asian countries appear to have very short lifespans, despite being kept in ideal conditions. Are these fish genetically predisposed to short lifespans because of in-breeding, high growth rate, or is it the conditions they have been raised in?

Variety – The most long-lived Goldfish are either Common or Comets.

Water quality – Goldfish kept in good water conditions throughout their lives will always live longer than those that aren’t.

Water temperature – Goldfish kept at constant high water temperatures will always have a high metabolism, whereas unheated fish have periods of low activity or hibernation. Cold water temperatures must prolong their lives, and constant high temperatures must correspondingly shorten their lives.

Diet/feeding - Long-lived fish almost always look underfed, let’s use the description "lean". Is the answer to a long life very light feeding?

Feed live foods and vegetable matter as often as possible, and feed dry prepared foods sparingly, especially when feeding fancy varieties.

Space - Some of the longest living Goldfish have never lived in a large aquarium or pond.

So, it appears the most important factors that we can control that govern the lifespan of Goldfish are water quality, water temperature, and diet/feeding.

Comments? Ideas? Feedback? I'd love to hear from you. Just reply to this e-zine and tell me what you think, or what topics you want covered.

Next Month's Topic

Genetic Diversity

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