do fish in captivity live longer?

Do Pet Fish In Captivity Live Longer?

5 Facts To Know

The majority of us will know the average expected lifespan of the fish that we keep in our aquariums. It is, however, lesser known, if at all, whether those lifespans are longer than they would be in a natural environment. So, with that in mind, lets ask the question ‘do pet fish in captivity live longer?’

Do pet fish in captivity live longer? The answer to this question, unfortunately, really is not that simple. There is very little information available, probably due to a lack of studies. In the wild environmental factors can play a part along with food sources which in many parts of the ocean are diminishing. Until more studies are carried out this question remains unconclusive.

However, what we can do is to look at these five facts we know about fish lifespans and see if these can be applied.

1. The Importance Of Good Genetics In Fish Lifespan

The lifespan of a fish, whether kept in captivity or wild, will be directly affected by genetic factors. These include size, heart efficiency, metabolism, age of sexual maturity, and in some cases, unfortunately, mutations and disease.

Whilst bad genetics, mutations and disease in particular, are found in wild specimens of the fish we keep in captivity, it is believed that they are not as prevalent. This is no doubt due to the captive breeding pool being a lot smaller than in the wild, and some irresponsible breeding!

There is no doubting that if you are unlucky enough to purchase a fish with bad genetics, that the chances are it will not live longer than its healthy wild counterparts. This, however, cannot be seen as THE answer to the question of do fish live longer in captivity as they are, hopefully, in the minority.

2. Environmental Factors Which May Affect Fish Lifespan

In their natural habitat fish can be affected by a number of factors that will have a direct impact on how long their lifespan will be. These are all things, that with proper care, have absolutely no, or very little effect captive fish.

The first factor to take into account is a disease that is left untreated, as they are in their natural habitat, can quickly kill the fish affected and be passed onto others. In an aquarium, however, this does not happen often as the affected fish is usually spotted, removed from the environment, and treat with medication.

Predation is the second factor which needs to be taken into account when considering the lifespans of captive and wild fish. Aquarium kept species are rarely put in with other fish that will predate upon them meaning that few fish lives are taken early due to this.

It is also worth mentioning, however, that some wild species do have natural defenses and behaviors to lower predation loss rates. These include chemical reactions, such as employed by the Boxfish, and also living in social groups and swimming closely packed together.

The third environmental factor that can have an effect wild fish lifespan is drought. This is pretty self explanatory since fish cannot live without water. Captive kept fish, of course, never come across this issue with their keepers ensuring their water is topped up.

Finally, but certainly not least important, is the starvation factor. This is definitely something that no captive fish should ever face. Their wild counterparts, on the other hand, can face this issue often. It is mainly due to overpopulation of their particular species and not enough food to go round.

Based on the environmental information above it would be very easy to state that captive fish, due to the care they receive, will live longer than their wild counterparts. However, this is all very much dependent on how we look after them, as you will see below.

How Care Can Effect The Lifespan Of A Fish

There are hundreds of articles out there that all talk about the correct care that every species of captive kept fish you can think of needs. These articles all vary, dependent on the needs of the certain species being discussed, but they also all have some things in common. These are that you must provide:

  • The correct size aquarium
  • The correct environment
  • Good nutrition
  • Regular maintenance and water changes
  • Treatment for illness

Providing all the above, it is generally accepted, will improve the chances of your pet fish living a long and healthy life equivalent of their wild relatives.

Not providing these things, on the other hand, will definitely shorten the lifespan of your fish, and ensure 100% that they will not outlive their wild counterparts. This could be due to disease, stunted growth, lack of nutrition, lack of heat, and many other things.

4. Conflict And How It Can Affect The Lifespan Of A Fish

It may sound strange to include conflict as a potential factor in the lifespan of a fish, but it can have a hugely negative effect on them. This is due to the stress which being bullied, chased, and having to fight can put their hearts under.

In their natural habitat fish which do not like each other will more than likely posture, chase, nip, and nudge each other in an attempt to get rid of the other one. These actions are accompanied by a sudden adrenaline rush which puts a strain on the heart. More than likely, however, the confrontation will be brief, one fish will flee, and both fishes heart rates will return to normal quickly.

In an aquarium, on the other hand, this situation is very different as neither fish can escape the other very far. This means that the chances are they will have regular and heated meetings with rushes of adrenaline being common. This puts an increased strain on the heart and can lead to a shortened lifespan.  

5. Species And How It Will Affect The Lifespan Of A Fish

So far we have only seen how certain factors could impact on the lifespan of a fish in the wild or captivity. We haven’t, however, been able to say with any certainty which will live longer, until now!

It is generally accepted in fish keeping circles that there are some species of fish that would not be able to live in the wild for anywhere near as long as they do in captivity. These species include, for example, the fancy Goldfish, fancy Guppy, and Betta Splenden.

The reason behind this thinking is that these particular species have been genetically enhanced by breeders over the years. They are all way more colorful than their wild counterparts and now have enhanced size fins and tails. This makes them ill equipped to survive in their natural habitats as they are less able to blend in and swim.

Perhaps a little more controversial is the belief that some fish, in particular species like the Red Tail Catfish, Common Plecostomus, and Arowana, for example, definitely have shorter lifespans in an aquarium than in the wild. This comes from the belief held by some fish keepers that we just can’t provide them with all their essential needs.

It is also worth bearing in mind that the fish we buy unless caught and not captive bred cannot really be judged by wild lifespan standards. After all, they, and probably many generations before them have never been in a wild environment, and probably couldn’t survive it if they were.

So Do Pet Fish Live Longer In Captivity?

The truth is that there is no definitive answer to this question as there are pros and cons, as shown above, for longer lifespans in both aquariums and natural environments. All we can say is that the best chance of our pet fish outliving their wild counterparts lies in the care that we provide.

Good nutrition, for example, will help your fish stay fit and healthy for longer, whilst the correct sized aquarium will keep them moving, give them room to grow, and keep their metabolism going strong. Providing the correct aquarium companions will also help as there will be no conflict to put stress on their hearts.

On an interesting note, recent studies into animals in captivity have shown that, contrary to popular belief, it is possible for wild animals to live longer in captivity than they do in their natural habitats. Out of 50 animals studied, recently in a zoo, 80% of them lived longer than their wild counterparts. Whilst this study did not include fish of any kind, it is still worth bearing in mind.  

Finally, it needs to be said, as a last thought, that whilst we cannot be certain that the fish we keep in our aquariums are living as long as they would in the wild, this is not the end of the world. Why? Because we can be certain that we are giving them, if not the longest life, the happiest and the healthiest. That, in itself, has to be of the utmost importance, right? And far better than pursuing the quest that our fish live forever!

About the Author

Joanne Burn

Joanne has been keeping fish for many years both freshwater and saltwater and has been writing for fish keeping websites and magazines for even longer. Her fishkeeping knowledge, research and writing skill makes her an essential member of the fishkeeping forever team.