How Long Do Fish Live as Pets?

Medically Reviewed by Kathleen Claussen, DVM on July 17, 2023
3 min read

Whether you’re considering getting a pet fish or you already have one, understanding the lifespan of pet fish will help you give your companions the best. With proper care, your fish can live for a long time.

To keep your fish healthy and happy throughout their life, you need to understand the needs of fish in general. There are thousands of fish breeds, and each one requires different care and feeding. It's important to remember that your fish’s health is a direct reflection of their environment. Keeping their tank clean will improve their well-being and lengthen their life. 

Fish breeds and lifespan. Fish have a bad reputation for short lives, but with proper care they can live for at least three to five years. Some breeds live a decade or longer. For example, the common goldfish, one of the most popular pet fish breeds, grows to be up to eight inches long and can live for twenty years. Other popular pet fish breeds include: 

  • Common pleco
  • Saifin plec/gibby
  • Bristlenose
  • Clown loach
  • Corydoras
  • Discus
  • Oscar
  • Fancy goldfish
  • Kissing gourami
  • Angelfish
  • Bala shark
  • Silver shark
  • Neon tetra
  • Tiger barb
  • Zebra/Leopard danio
  • Boesemani rainbowfish
  • Guppy
  • Molly
  • Platy
  • Ram cichlid
  • Sailfin molly

The role of tank quality. Keep in mind that the size of your fish tank should serve your fish through their lifelong growth and not just their size when you first get them. Think about where you can put a tank in your home that's away from windows and air conditioners. This will help to regulate the water temperature and reduce algae growth in the water.

Talk to your local fish breeder, pet store, or veterinarian’s office about the requirements for your specific fish breed. Maintaining a certain pH level is important for many fish breeds. 

Don’t use tap water unless you allow it to sit for a few days. This is because there are additives like chlorine and other compounds. Alternately, use a de-chlorinator before moving the water to your fish tank.

Keep your fish’s water clean but not sterile. Good bacteria grow in the water and help maintain your fish’s health. Change the water 10%-15% at a time to allow for the introduction of fresh water without shocking your pet’s system with a dramatic change.

Role of nutrition. Flake and pellet food are most commonly used for pet fish. You can sprinkle food in the morning and evening, but be careful not to overfeed. Obesity in fish is life-threatening and can shorten their lifespan. If you want to supplement their diet, consider: 

  • Freeze-dried Tubifex worms
  • Mosquito larva
  • Bloodworms
  • Daphnia
  • Brine shrimp
  • Vegetables like boiled peas or lettuce

Maintain a low-stress environment. Stress affects all of us, and fish are not immune. Since fish like to hide, make sure there are real or plastic plants your fish can swim between. If you have other pets, like cats or dogs, keep them away from the tank so your fish doesn’t feel threatened.

Consider which breeds share a tank. Different breeds of fish aren’t always compatible. Talk to your vet or pet store before introducing new fish to a tank. In fact, it’s a good idea to keep new fish separated for a few days to a week. This ensures they are healthy, so they don’t introduce an illness to your other fish.

Find a fish veterinarian. You may not think of fish getting sick or needing specialized care, but they do. If you want your fish to live a long and healthy life, be sure to have a vet on call for questions and checkups. Since not all veterinarians treat fish, you’ll want to do some research and find a specialist in your area.

Signs of fish illnesses. There are a number of signs you should watch for that may indicate your fish is sick:

  • Being disoriented
  • Swimming in an odd pattern or upside down
  • Not eating
  • White spots appearing on scales or gills
  • Discoloration
  • Trouble breathing, such as staying at the surface of water
  • Bulging eyes
  • Mucus appearing on the body
  • Rubbing against hard surfaces
  • Isolating oneself from other fish
  • Sores
  • Bloating
  • Change in shape, size, or appearance

If you have any concerns about the health of your fish, check with your veterinarian. Illnesses affecting your fish may include:

  • Physical injury
  • Parasites 
  • Bacterial infections 
  • Fungal infections 
  • Fish pox (wart-like growths) that are caused by a fish herpes virus 
  • Ammonia or chlorine poisoning because of poor water quality