How long do fish live? Goldfish, betta and aquarium fish lifespans

Most small aquarium fish live about 2 to 5 years, bettas usually 3 to 5 years, and goldfish 10 to 15 years or more when they have enough room. Bigger fish, such as oscars and many plecos, often live 10 to 20 years. Good water, a big enough tank and the right food are what get a fish to the top of its range.

Published figures vary a lot, because few people keep careful records. Treat the numbers below as rough guides, not promises.

Typical lifespans

Fish	Typical lifespan with good care	Notes
Neon tetra and other small tetras	3–5 years	Often shorter if bought weak or kept in unstable water
Guppy	1–3 years	Livebearers tend to be short-lived; fancy males often less
Betta	3–5 years	Sources range from 2 to 5; bettas are often about a year old when sold
Goldfish (common, comet)	10–15+ years	Can pass 20; the longest recorded captive goldfish lived 43 years
Fancy goldfish	5–10 years	Rounded body shapes bring swim bladder and organ problems
Angelfish	8–12 years
Corydoras	5–10 years	Some reach 15; figures vary widely
Bristlenose pleco	5–10+ years	Estimates vary a lot between sources
Zebra pleco (L046)	10–15+ years	Based on keeper reports; little published data
Common pleco	15–20 years	Grows very large; needs a very large tank
Oscar	10–15+ years	Needs a very large tank
Discus, clown loach	10–15 years

A rough rule: small fish and livebearers live shorter lives; big fish and egg-layers live longer.

Goldfish lifespan

A goldfish should outlive most dogs. RSPCA Australia puts the average at about 10 to 15 years, with some living to 30. Most pet goldfish die far younger, often within a year or two, because they are kept in bowls or small tanks where waste builds up and they can't grow properly. A single common goldfish needs a large tank or a pond; fancy goldfish need less, but still far more than a bowl. In the wild and in ponds, goldfish have lived past 40.

Betta lifespan

Bettas usually live 3 to 5 years, although some databases give only about 2. Part of the gap is that bettas are sold as adults, often about a year old, so you won't have them for their whole life. Keep them warm (around 26 °C, 79 °F), in a heated, filtered tank of at least 19 litres (5 US gallons), with gentle flow and a lid, and don't overfeed. See betta not eating and betta fin rot.

How to tell if it's old age

A bent or curved spine that appears slowly over months.
Faded colour and duller fins.
Slowing down: resting more, swimming less, slower to reach food.
Thinning: a slimmer body and a sunken back even though it still eats.
Cloudy eyes (cataracts) in some fish.
Ragged fin edges that heal slowly.
In females, no more eggs or fry.

When it's a problem: old age or illness?

Likely old age: the fish is near the top of its typical lifespan, the changes came on slowly over weeks or months, your water tests are fine, and the other fish are healthy.
Likely illness: the fish is young, the changes came on in days, or there are spots, fuzz, red streaks, bulging eyes, raised scales, clamped fins or rapid breathing. Other fish showing signs is a strong clue it's the water or a disease, not age. See fish dying, dropsy and popeye.
Always test the water first. Bad water makes young fish look old.

What to do right now

Test ammonia, nitrite, nitrate, pH and temperature to rule out a water problem.
Look closely for signs of disease (see the list above).
Check that the fish is eating. Watch a full feeding.
Check it isn't being bullied. Old, slow fish become targets. See aggression.
Make life easier: see the next section.

What to do next: keeping an old fish comfortable

Keep the water extra clean with regular partial water changes. Older fish handle poor water less well.
Feed small, soft, easy-to-reach meals: sinking pellets for fish that can't get to the surface fast, soaked pellets, gel foods or frozen foods. Feed near where the fish rests.
Turn the flow down so it doesn't have to fight the current, and guard the filter intake (see filter intake).
Give it resting places: broad leaves, smooth caves, flat stones near the surface.
Move bullies, or move the old fish to a quiet tank.
Keep temperature stable and avoid big changes.

When it's time to say goodbye

If an old fish can no longer eat, can't stay upright, or is lying on the bottom gasping, a humane end may be kinder than waiting. Never flush a live fish or put it in the freezer. Our dropsy guide explains the clove-oil method, or a fish vet can do it for you.

Products that help

A properly sized tank with a filter and heater: the single biggest factor in how long fish live.
Water test kit (ammonia, nitrite, nitrate, pH): to rule out water problems.
Water conditioner: for every water change.
Sinking pellets, gel foods and frozen foods: easy meals for slow or old fish.
Intake sponge and outlet baffle: to keep the flow gentle.
Hospital tank or breeder box: a quiet place for an old or weak fish.
Keep on hand: clove oil, in case a humane end is needed.

How to help fish live longer

Skip the bowl. Tiny bowls have no filter or heater, waste builds up fast, and temperature swings every day. Fish in them live a fraction of their natural lives.
Buy a tank for the fish's adult size, not its size in the shop.
Cycle the tank before adding fish: see cycling.
Do regular partial water changes and keep nitrates low.
Feed the right food in the right amount: see feeding and overfeeding.
Quarantine new fish so you don't bring in disease.
Buy healthy fish from a good shop or breeder. Some heavily line-bred fish (very round fancy goldfish, balloon mollies, some colour morphs) are naturally shorter-lived.
Keep calm, compatible tankmates.

Why fish die young

Most aquarium fish don't die of old age. They die of small tanks, poor water, the wrong temperature, the wrong food, stress or disease, often in their first year. The fish that reach old age are usually kept in stable, clean, roomy tanks with suitable tankmates.

When to get help

If a young fish shows "old age" signs, or several fish decline at once, it's probably not age. Test the water and ask an experienced keeper or a fish vet.
If a fish is suffering and you can't do a humane end yourself, a fish vet can.

In the game

Multiple Tank Syndrome doesn't have a lifespan or old-age card yet.