What’s A Goldfish’s Attention Span? A Complete Walkthrough of This Smart Fish Species

Last Update:
Goldfish Attention Span

There is a common misconception created by pop culture myths that a goldfish’s attention span lasts only anywhere from three seconds to nine seconds!

However, according to the BBC, we’ve been wrongly smearing the name and intelligence of goldfish!

I have done a ton of research on the topic and there is absolutely no study or research to back up any claim that goldfish, or any fish for that matter, have a very short attention span.

In fact, I have found evidence to the contrary which we will discuss in this article as well a lot of other features of the goldfish, as follows:

  • Goldfish Behavior
  • How Big Do Goldfish Get?
  • Goldfish Lifespan        
  • What Is A Suitable Environment For Goldfish?       
  • Other Names Used To Refer To A Goldfish    
  • Nutrition Needs
  • Pairing With Other Fish Species   
  • Price
  • How To Introduce Goldfish In Fish Tanks

How Intelligent Are Goldfish? 

The popular myth that goldfish only have an attention span of three seconds has been disproven! Goldfish are more intelligent than most people know. The myth was proven false by a fifteen-year-old boy and his pet goldfish nonetheless! 

The boy decided to do an experiment to test if what they say is true about goldfish. He placed a red Lego block in the fish’s aquarium and then sprinkled the fish’s food around the block. Eventually, the fish learned to associate the red block with feeding time and would swim over to the block before being fed! 

Once the fish was doing this consistently, the boy stopped using the red block for one week. After one week, he reintroduced the red block, and the fish immediately swam over to the block in anticipation of food! This shows that goldfish have a memory of at least a week, if not longer! 

Research has also shown that they are able to recognize humans, find their way through mazes, and even learn to push a ball into a net! These are not dumb fish by any means. Now that we have learned a little bit about how intelligent goldfish are, let’s discuss some key information about them. 

Goldfish Behavior 

Goldfish are actually quite social fish. They will rarely behave aggressively towards other fish. The only time they may act aggressively is if the tank is overcrowded and they feel they have to compete for resources like space and food. In a healthy environment, goldfish love to play, explore, hang out with their tank mates, and even take a little snooze during the day! 

How Big Do Goldfish Get? 

Common goldfish, those with slim bodies and single tails, often reach up to 10 inches in length. Fancy goldfish, those with rounded bodies and double tails, usually reach up to 8 inches in length. Most fish bought in pet stores are babies, so keep in mind that those cute little fish are going to grow. 

Goldfish Lifespan 

A goldfish kept in good condition and with proper care will, on average, live between ten and fifteen years. However, it is not unheard of for a goldfish to live as long as thirty years!

However, because of misinformation regarding proper care for a goldfish, most, on average, only live about four to five years. This can vary, too, depending on the type of goldfish.

For example, Fancy Goldfish are much less hardy than common goldfish and are more susceptible to disease caused by poor tank conditions. This is why the health of a tank is so important. 

What Is A Suitable Environment For Goldfish? 

At the very minimum, a single young goldfish needs at least a ten-gallon tank, but it will need a bigger tank as it gets bigger. It is a myth that goldfish only grow to the size of their tank.

They should never be kept in a bowl! Instead, it is recommended that a single full-grown Goldfish be kept in a 20-gallon tank, with an extra 10 gallons being necessary for every added goldfish. For example, if you know you are going to want to have 4 to 5 Goldfish, you’ll need to have a 50 to 60-gallon tank. 

They are cold water fish, but many do best in a bit warmer of a temperature. For most goldfish, the ideal temperature would be around 71 degrees Fahrenheit.

However, this can vary among the different goldfish breeds, with some preferring temperatures as cold as 65 degrees Fahrenheit and others preferring temperatures as high as 75 degrees Fahrenheit. They are very hardy and adaptable fish but do best with a pH of between 6.5 and 8.5. 

Other Names Used To Refer To A Goldfish

The scientific name for Goldfish is Carassius Auratus. Auratus actually means “overlaid with gold,” hence their name! There are well over 200 different breeds of goldfish.

To mention a few names you may or may not have heard before, we have the Comet goldfish, the Shubunkin goldfish, the Wakin goldfish, the Japanese Ryukin, the Fancy Fantail, the Veiltail, the Broadtail Moor, or Blacktail Moor, and the Oranda just to name a few! 

Nutrition Needs

Goldfish are omnivores and will eat just about anything. That being said, though, they do have some more specific nutritional needs. In most cases, flakes should be avoided. Flakes tend to just sit on the surface of the water, forcing the goldfish to gulp in air as it is eating, which can be detrimental.

Instead, sinking pellets are usually the best option for dry food. However, make sure your soak dry food for a minute or two in water before feeding it to your fish. If a fish eats too much dry food with not enough moisture, the food will expand in its belly, which can lead to bloating.

Other food options include defrosted frozen food like bloodworms, brine shrimp, and daphnia. You can also feed them greens like spinach, zucchini, and broccoli florets. And, of course, live plants can be a good treat for goldfish to nibble on. 

Pairing With Other Fish Species

Goldfish will eat just about anything, including other fish species and even their own young! That being said, however, goldfish are peaceful creatures so long as they can’t fit the other fish in their mouth.

There are a few things to consider when deciding if and what kind of tank mate you will get your goldfish. First, the other fish will need to have the same temperature requirements as your goldfish. This is usually somewhere between 65 and 75 degrees Fahrenheit, depending on the goldfish.

Secondly, the fish will also need to be big enough, at least 3-4 inches, so that the goldfish isn’t tempted to eat them. In most cases, it is best to choose similarly sized fish as well as fish with similar swimming abilities.

Lastly, the fish you choose will need to be a non-aggressive type as well. 

Side Note

Not all goldfish should be kept together. For example, Fancy Goldfish have big round bodies with double tails. They aren’t the fastest swimmers because of their size. If paired with a leaner and faster single-tailed goldfish, they could struggle to get their fair share of food.

And while goldfish are non-aggressive, some can exhibit some bullying behaviors if paired with fish that aren’t as fast or big as them. 


On average, most people spend less than 40 dollars on a pet goldfish. However, this can vary widely since you can buy a feeder goldfish for less than 17 cents sometimes, which can actually make a perfectly good pet goldfish!

Many, when properly cared for, will grow quite large. You can also buy less common goldfish and spend upwards of 300 dollars on them! In fact, the most expensive goldfish in the world right now is the incredibly rare Tosakin Goldfish which can easily cost upwards of 600 dollars!!

How To Introduce Goldfish In Fish Tanks 

Adding goldfish into a fish tank can be a bit of a process, but it is worth it to do it slowly so as not to shock the fish. You’ll also need to make sure you properly cycle your tank and get it ready to add fish.

The cycling process can take anywhere from two to eight weeks, but it is well worth the wait to ensure you have a healthy habitat for your new fish! In a nutshell, you’ll know the cycling process is complete once ammonia and nitrite levels read zero and nitrate levels are high.

Once your tank is ready, keep your fish in the bag it came in and let it sit in the tank for about 20 minutes. This will help the temperature of the water in the bag to even out with the temperature of the tank water.

From there, open the bag and add about a cup of tank water. Do this every fifteen minutes until there is more tank water than bag water left in the bag. Once that happens, you can let your fish swim out of the bag and remove the bag from the tank. Just remember to keep a close eye on the tank levels for the next couple of days because adding in a new fish can throw the system a little bit out of whack, so some changes may be necessary. 

Goldfish’s Attention Span: Final Thoughts

Goldfish are incredibly smart creatures who deserve the absolute best care and quality of life we can provide them. Long gone are the days where we keep our goldfish in tiny fish bowls where their fins are bumping the sides. Instead, they deserve all the room they need to be able to swim, play, and explore! 


Leave a Comment