Aquarium Life Expectancy: How Long Will Your Fish Live?

Written and verified by the lawyer Francisco María García

Last update: 21 December, 2022

If you decide to get an aquarium for your home, you’ll need to learn a bit about the species you’re going to be keeping in it. Fish are living beings that need proper care to stay in good health and have a long life expectancy when you’re keeping them in an aquarium.

How long do fish live?

There isn’t one exact answer to that question, unfortunately. How long a fish lives depends a lot on internal and external factors that might not be under your control.

Aside from that, there are lots of different species of fish, and they all have a different metabolism. In other words, every species, and every individual fish, has a different life expectancy.

On top of that, how long a fish might live also has a direct link to its habitat. In general, fish that live in captivity tend to live longer than fish in rivers and seas. That’s because there aren’t any predators, and they get food on a regular basis.

You should never forget that fish are sensitive creatures. Their health depends a lot on having a proper diet, a clean environment, and the right climate. They’re very vulnerable and sensitive when you keep them in an aquarium.

What’s the life expectancy of fish in an aquarium?

As we said, the life expectancy of a fish doesn’t just depend on its species, but also the kind of care you provide it with. But just to give you an idea of what we mean, some fish live a few hours, and some live 10-15 years in a tank.

The small fish most commonly sold in pet stores are extremely young. They’re usually only 2-3 months old. This early stage of their life is crucial, because they’re still developing into adults.

With a good diet, a big space, and a positive environment, your fish will be able to grow big and strong. Just that fact will already make a big impact on its life expectancy. On the other hand, if it’s in a negative environment with a poor diet, it could die in a few days or even hours.

You also need to understand the difference between an aquarium and a fish bowl. Fish that live in small bowls and tanks generally don’t live longer than 2-3 years. Having said that, some experts say that their life expectancy might be a bit higher if they’re not under stress.

Meanwhile, fish that live in a big aquarium that replicates ideal conditions in the wild can live longer than a decade. This, of course, depends on the individual species. For example, common carp can live longer than 15 years when you take good care of them!

It’s not a firm rule, but larger, stronger fish do tend to be tougher. In many cases, they have a longer life expectancy in an aquarium than smaller, more fragile species.

The life expectancy of the most popular aquarium fish

Now, we’re going to take a look at the life expectancy of some of the most popular aquarium fish species.

• Clownfish: the species immortalized by the movie Finding Nemo can live between 5 and 10 years. They don’t need too much care, which makes them a great choice for owners without much experience.
• Goldfish: the goldfish is a very fragile species that generally only lives 2-3 years. These little creatures require a meticulous care routine involving their water, diet, and environment, because they get sick very easily.
• Guppies: These fish are famous for the unique colors on their bodies. This freshwater species native to the Americas is also pretty fragile, and only has a life expectancy of about two years. You also have to keep careful watch over the water temperature in their aquarium.

How long do fish live in their natural habitats?

Considering all the different species of fresh and saltwater fish in all kinds of ecosystems and climates, it’s impossible to give a single exact figure for life expectancy. For example, there are sturgeons that have made it past 100 years old, although that’s uncommon even for their species.

In general, the life expectancy of a saltwater fish is around 20 years. Freshwater fish tend to live to about 15. Another interesting tidbit is that fish that live in cold water tend to live longer than ones that live in warm water.