How long do fish live...?

Fish lifespans vary dramatically by species, environment, and care.

Some fish live only a few months, while others can survive for centuries.

Here’s a detailed breakdown:

Typical Fish Lifespans by Type

• Small freshwater fish (e.g., guppies, tetras)

1–5 years

Popular aquarium fish; lifespan depends on water quality and diet.

• Goldfish / Koi

10–30 years (common), 40+ years (well cared for)

Fancy goldfish ~10–15 years; Koi can reach 50+ years; record koi “Hanako” lived 226 years.

• Angelfish / Cichlids

10–20 years

In aquariums; larger cichlids may reach 25 years.

• Betta / Siamese Fighting Fish

2–5 years

Short-lived unless very carefully maintained.

• Salmon / Trout

3–8 years

Many die after spawning (semelparous species).

• Tuna

15–50 years

Some large species (e.g., bluefin tuna) can live decades.

• Sharks (various species)

20–500+ years

- Great white ~70 years- Greenland shark estimated 272+ years (oldest vertebrate)

• Deep-sea fish

50–200+ years

Cold, low-predator environments allow extreme longevity.

• Ocean Quahog / Clams

100–500+ years

Bivalves like Ming the clam reached 507 years.

• Sturgeon

50–100+ years

Large freshwater species, slow-growing; some 150+ years.

Factors Affecting Fish Lifespan

Species & Genetics: Some fish are naturally short-lived (e.g., guppies), while others grow slowly and live longer (e.g., sturgeon, sharks).

Environment: Cold-water species with fewer predators live longer; aquarium fish often live shorter lives without ideal care.

Diet & Care: Proper nutrition, clean water, and stress-free habitats significantly extend lifespan.

Size: Larger fish generally live longer; e.g., small goldfish vs. large koi or sturgeon.

Reproduction Strategy: Semelparous fish (like salmon) die after spawning; iteroparous fish reproduce multiple times and live longer.

There isn’t a single simple number for “how many fish species are in decline” in the UK, because scientists usually track fish stocks (populations) rather than counting individual species in a yes/no way.

But the latest research gives a clear picture:

Key figures (UK fish)

Around 105 fish stocks are assessed in UK waters. (� envirolink.org)

17 of those are in a critical state (both overfished and overexploited). (� envirolink.org)

About 1 in 6 stocks (~17%) are critically depleted and still being overfished. (� Oceana UK)

Only ~41% of UK fish stocks are considered healthy, meaning the majority are not. (� Phys.org)

What that means in plain terms

A significant share of UK fish populations are declining or in poor condition.

At least dozens of fish populations (stocks) are already in serious decline.

Many more are under pressure or not sustainably managed, even if not yet collapsed.

Important nuance

“Fish species in decline” is harder to pin down because:

A single species (like cod or herring) can have multiple regional stocks, some worse than others.

Reports therefore focus on stocks (populations) rather than species counts.

Bottom line:

Roughly tens of UK fish populations (at least ~17) are in serious decline, and well over half are not in a healthy state overall.

Fact: The Greenland shark is the longest-living vertebrate known, estimated to live 272–500 years, far exceeding typical human lifespans.

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