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Fun Fish Facts

Fun Fish Facts

Fun Fish Facts (View larger version)

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  • Goldfish are descendants of carp and have their origins in China.

  • There are hundreds of varieties of goldfish found around the world.

  • Goldfish have teeth in their throat – called ‘pharyngeal teeth’ – which are used to help them crush their food.

  • Goldfish may grow as long as 23 inches and weigh nearly 7 pounds, although this is rare.

  • Goldfish do not have stomachs. Different parts of their intestines do the job of breaking down food and absorbing nutrients.

  • Goldfish can live up to 30 years - longer than most other aquarium fish.

  • In the 18th century, members of the European aristocracy would remove goldfish from their ponds and place them into decorative bowls for special occasions.

  • A goldfish cannot be reliably sexed until they are at least 1 year of age.

  • It is easiest to identify the distinguishing features between male and female goldfish during the breeding season. At that time, males develop white, pimple-like spots on their gills. The females’ abdomen becomes enlarged. Another distinguishing feature is the size and shape of the vent located near the anal fin. A male’s vent tends to be narrow, concave and more oval. A female’s vent is more convex and round.

  • Goldfish courtship can create quite a splash in your aquarium! Once the female reaches sexual maturation, she begins to release pheromones. This triggers the male to begin his pursuit by chasing the female around and poking at her stomach. This behavior is often confused with fighting and can become quite aggressive. The male is trying to get the female to release her eggs which are held in the abdomen. It is best to have a planted area in the tank for her to lay her eggs. The female lays up to 500 eggs at a time. Once the eggs are released, the male fertilizes them. Goldfish will eat their own eggs, so it is best to remove them and place them in a different tank.

  • Contrary to popular belief, the goldfish memory span is far beyond three seconds. Goldfish have the capacity to learn and adopt patterns of behavior. Yup, this means you can train your goldfish!

  • A school of fish is known as a ‘troubling’.

  • Goldfish do not blink…because they have no eyelids! And yes, this means they sleep with their eyes open.

13 comments
Amanda DaPatches
Amanda DaPatches

I am extremely disappointed in in NatGeo for condoning the pop-culture, ideal image of the goldfish in a bowl. How can you air cool, educational programming such as "Monster Fish 600lb. Giant Goldfish" which was about a relative of the goldfish, the giant carp, and yet advocate for animal cruelty in this way? To have anything labeled as the "Fish Bowl" perpetuates myths about fish husbandry and do the animals a great disservice. This entire article is completely misleading when coupled with this "Fish Bowl" event as many of these facts do not apply to goldfish kept in a bowl.

Even if the fish shown were only kept in a bowl for the show segments, it is still promoting animal cruelty as people will take it for face value. It would have been amazing and super progressive if you had shown these fish in a proper home with proper stocking levels and let the audience know that fishbowls are not proper aquatic cages. However, I'm sure that it would have also ticked off the pet store industry that you make money on... Making a difference in the lives of these "disposable" creatures by busting myths in an entertaining way is less important than making a buck.

Alex Fleming
Alex Fleming

National Geographic, what about all the kids that go out and will be buying a bowl for their goldfish, following your influence? What are you going to say to them and how will you explain to them that you let them know that this was okay - when their fish dies from suffocation, ammonia poisoning and gross horrible stunting? 


A 20" fish won't even fit in a bowl. I wouldn't keep a goldfish in a bowl for anything over a week -they grow that fast! They're poop machines, they'll eventually burn their gills through ammonia poisoning because of inadequate filtration (unless someone is going to change the water every. single. day). 


I'm disappointed in you, National Geographic. The magazine that I looked up to as a kid, and I followed its word like truth. I know how devastated I felt when I grew up and realized how I killed several goldfish after keeping them in a bowl - this is abuse and neglect, and I'm ashamed to see Nat Geo support the outdated keeping of fish in bowls.

Ute Goldfishdoctor
Ute Goldfishdoctor

A fish bowl is actually plain animal abuse - it holds so little water and has no room for a proper filter to get rid of harmful ammonia and nitrite. Because there will be a lot of bioload, the ammonia will be present in the bowl really quick, and will poison the fish. This can cause a lot of diseases or even death, in most cases.

A bowl doesn't have any space for a filter or eventually a heater. And for a goldfish, which can grow up to 23 inches according to these facts, it won't even fit inside a bowl.


For fish lovers like me, a bowl is a terrible sight to see - esspecially when it's being glorified like this. I'm disappointed :( I'd love to see proper fish care being promoted, instead of bowls. Fish are not decorations, but living animals who deserve proper care. 

Marijke Aquariadise
Marijke Aquariadise

 Whether the fish has only been kept in the bowl temporarily to film it doesn't matter. It's not necessarily about these fish in particular, but about the message this is sending. Nat Geo is telling people it's okay to keep fish in a bowl even though the most basic rule of fishkeeping is that you cannot. It is cruelty. A channel that serves to educate should do just that - not keep this myth in existence. If you really want to teach fun goldfish facts, then start at the most basic one. If this site would mention that bowls are not okay it would influence so many people and it could really make a difference, but instead they choose not to, which is very disappointing. Fish are not decorations, they are living animals and Nat Geo should aim to teach people that. 

Christine Nguyen
Christine Nguyen

It's so disappointing to see national geographic, a well-known and very influential source, glorify the goldfish bowl like this. Because goldfish don't have a true stomach, food passes through their system very quickly. Thus, the waste builds up quickly as well, racking up the levels of ammonia in the bowl. The ammonia burns the fish's body and gills and results in a terribly slow and painful death. 


The fishbowl is animal cruelty. 


An animal that "may grow as long as 23 inches and weigh nearly 7 pounds" would not even fit inside a fish bowl so why is it shown to be a suitable home for this animal? Those 2 inch goldfish will one day be  at least 6 inches but they won't live to see that day as they continue to live in the filthy, poorly oxygenated, and the illogically sized bowl. 


Even if the fish shown on here don't live in that bowl permanently, this show is promoting and influencing their viewers to go out and buy goldfish to keep in goldfish bowls. 


Those fish won't last a month. Or worse, they'll live a maximum of two to three painful years... 


If nat geo should be showing anything on goldfish, they should be breaking the myths of bowl culture and promoting the ***PROPER care for these animals. 


This truly deserves a SMH. 


***Proper care for a goldfish means that they have adequate filtration and aeration. As for tank size, popular and proven knowledge recommends that a single goldfish should be given at least 15-20 gallons of space/water. Tank maintenance should be done on a weekly basis. 


Arla Halvorsen
Arla Halvorsen

I'm sure they only kept them in the bowl for the show segments. They look pretty healthy to me. I love my fish and I put them in bowls while I change their water, which can take up to a half an hour when their tank needs a good cleaning! They don't seem to mind... much. True their anger knows no bounds, but they're not really much angrier than they are any other time!! :) My fish are bettas and they LOVE their shrimps and flakes. My female betta gave her first trapdoor snail a good darting when I first put him in, but then they became pals. She would get kinda jealous when I would feed him, though. She would try to steal his flakes when I would feed him while he was at the surface. My male would do the same to his snail pal!! I love my fish, I keep them in nice big aquariums with moss and betta bulbs and bubbling undergravel filters and heaters that keep the water steady between 78 and 82 degrees, and I feel confident that the people at National Geographic wouldn't treat their fish with any less care than I would mine. I know the same can't be said for every private fish owner out there, but I've always heard that whenever an animal is in a TV show or movie someone from an animal protection agency is on hand to make sure they're cared for properly and not abused. At least nowadays, I cringe when I see an old movie or TV show with an animal on it... :(

Nicole Edwards
Nicole Edwards

I agree completely with Charli. Goldfish and all fish are not decorations and should be cared for with as much effort and love as you would give to any pet! Fishkeeping is such a fun/relaxing/rewarding hobby. But with any hobby and pet do your research so you can provide the best possible care for your animal no matter the size. 

Charli Haskill
Charli Haskill

Goldfish are amazing creatures and should never be kept in a bowl. Actually no fish should ever be kept in a small bowl with no filtration, not even a betta.

Fancy goldfish (short bodied/fantail), especially, need at least 30g of space for the first fish depending on the individual. I say 'depending' because I have a beautiful goldfish named Jey. He's only three years old and already the size of a softball. Still growing every day. Jey would never be comfortable in anything under 40g because of his size. He and his tankmates are in a 75g with heavy filtration and weekly water changes. I'm so happy to see them reaching their potential. Long bodied- single tail goldfish should have much more space. These fish can live 20+ years with the proper care.

I hope everyone else gives their goldies a chance by ditching the bowls. Happy and healthy goldies are much more rewarding.

Elizabeth H.
Elizabeth H.

Goldfish should also never be kept in bowls long term due to their large adult size (they only reach this if kept properly) and the lack of surface area in a bowl for beneficial bacteria to grow and convert ammonia to the less harmful nitrate. Goldfish need a minimum of 15 gallons per fish. Always do your research before you purchase a pet! No matter how small!! 

candace chapman
candace chapman

My daughter is in LOVE with this. Especially since we just got a Goldie about a week ago. #WINNING

Arla Halvorsen
Arla Halvorsen

I know my betta fish will enjoy this!! :) Shoutouts to Archie and Betta Davis aka Fishy Girl!!

Arla Halvorsen
Arla Halvorsen

I'm so excited!! I love this idea! I hope we do it every year!!

Alex Fleming
Alex Fleming

I'd also just like to mention that here in NZ bowls haven't been sold in our large chain stores for years. The keeping of fish in bowls is seriously behind in time and I can't believe people still do it ;_;