Pure Goldfish: Your Ultimate Resource for Goldfish Keeping!2018-02-19T04:00:55+00:00



Pure Goldfish: Your Ultimate Resource for Goldfish Keeping!

Are you absolutely clueless about goldfish?

Do you want to learn more about this amazing aquatic pet that has captivated the hearts of millions?

You have come to the right place!

At Pure Goldfish, we are absolutely obsessed with anything and everything goldfish-related.

Let’s get the lowdown on the world’s most popular aquarium fish…

General Information & Biology

Goldfish are pretty adorable animals. But they are also SUPER interesting.

Scientifically, they are freshwater creatures called Carassius auratus.

Betcha didn’t know that fancy Latin name actually means “gilded fish!”

And for good reason…


Most goldfishs’ scales are metallic and flashy, making them look like they are made of precious metal.


There are now a wide variety of scale types, so not all goldfish are gold – or even shiny.

Some are silver, white, brown, black or even calico!

Funny thing is:

The typical “gold” fish is actually more of an orange color, which is technically called red.

Are you confused yet? 😉

[Click here to read more interesting facts…]

Size and weight

Like snowflakes, there is a TON of variation in size and appearance in goldfish land.

The smaller ones may reach a length of 6” whereas larger breeds can grow to be over a foot long! The largest known goldfish weighed in at over 5 pounds.

Some can get to be the size of a cat!

The world record for the longest goldfish used to be held by a fish named Bruce at 15 inches long, but was broken in recent years by an even bigger fish!


Goldfish are foragers by nature, and their bodies are perfectly suited for doing what they love best:


They have a vacuum-like mouth, a powerful muscular system for propelling their fins through water and a special organ called the “lateral line” to sense currents and depth.

So yes, goldfish do have a sixth sense!

(Psst – did you know a goldfish has taste buds on its lips?)


There is a reason goldfish owners affectionately refer to their pets as “water puppies” and give them creative names.

Nearly everyone agrees that they are chock full of personality.

Contrary to popular belief, goldfish are actually quite intelligent.  They can be taught to perform tricks for food and even have significant memory abilities!

Their incredible ability to recognize the faces of their owners (and even hear them approaching) often sets off a begging frenzy, which consists of:

  • Swimming rapidly back and forth as though they are trying to break through the glass
  • Pumping their mouths open and closed
  • Making “kissing” noises at the top of the tank
  • And sometimes even splashing water surface with their fins!

With a bit of patience, they can actually learn to eat out of your hand (which is, of course, adorable).

Goldfish can be very social creatures and can be seen interacting with other goldies in humorous ways.

Do they actually form friendships with their companions?

It’s hard to know for sure, but there seems to be evidence that they do. They can also do quite well by themselves.

In ponds, goldfish will often “school,” which keeps them safe from predators.

[Click here to learn about what fish make good tank mates for goldfish…]

The Unusual History of the Goldfish

A goldie’s relatives include koi (a cousin) and the carp (it’s granddaddy).

Carp are a simple fish that are found in the wild in a kind of drab, olive-brown color.  What we see today may not look a whole lot like their ancestor, but the fact remains that goldfish are just modified carp.

Get this:

It was through hundreds of years of careful, selective breeding that goldfish have been domesticated from these humble animals and transformed into the colorful, sometimes ornate fish that they are.

(Actually, they were probably the first domesticated fish ever!).

This happened in China over a thousand years ago.

People in the Jin Dynasty who reared the carp for food noticed that sometimes they produced silver, red or yellow offspring.

Yellow coloring (true “gold”) used to be the royal color in China, so high-status noblemen began collecting the yellow variety and keeping them in ornamental ponds.

In fact…

It was illegal for peasants to own a yellow goldfish!

To get around this rule, people started breeding goldfish that were more orange-red instead.

That’s why orange ones are more common today – even though the yellow ones are easier to produce because of their genetics.

Eventually goldfish began to be kept indoors in large ceramic pots (glass didn’t come until much later!).

They continued to be selectively bred until the more delicate fancy goldfish appeared on the scene, and a long time after that.

During this time many goldfish were bred to be viewed from above.


You can tell a koi from a goldfish mostly by the little whiskers – called barbels – the koi has on each side of its mouth.

But just because goldfish and koi share the same genes doesn’t mean they get along!

(Goldfish should only be kept with other goldfish.)

[Click here to learn more about where goldfish come from…]

The Many Incredible Breeds of Goldfish

Thanks to so much hard work on the part of breeders both ancient and modern, the goldfish comes in an incredible array of shapes, sizes, colors, fin types and unusual body features.

No two are ever the same.

Did you know that there are over 120 different varieties of goldfish?!

There is something for every personality type – from the sleek and simple to the elaborate and showy.

All goldfish fall under two main categories:

  • Slim-bodied, which have a long, narrow body shape and grow to be over a foot long
  • Egg-shaped, which have a rounded body, paired fins and don’t get quite as large

Slim-bodied goldfish typically do better in ponds, whereas egg-shaped goldfish are more delicate and require indoor care in most cases.

[Click here to see a list of 21 incredible types of goldfish]

These are some of the most popular breeds of goldfish available today:

  • Black Moor – A popular variety of telescope with a deep velvety black color
  • Bubble eye – Known for its huge, fluid-filled sacks that grow under each eye
  • Butterfly – Bred to have a tail fin shaped like a butterfly when viewed from above
  • Celestial eye – A more uncommon variety with no dorsal fin and shiny, big, upturned eyes
  • Comet – This fish is similar to the common goldfish, but with a longer, trailing tail
  • Common – Probably the most popular variety of goldfish, sold as feeders at pet stores
  • Fantail – The simplest of all the fancy goldfish, with a double tail. Very common.
  • Jikin – This goldfish is a slim-bodied goldfish with a short double tail and unique red and white markings
  • Lionhead – A goldfish without a dorsal fin and short tail
  • Oranda – A fancy goldfish with a puffy “cap” on top of its head called a wen
  • Pearlscale – Famous for its raised, dome-shaped scales that look like pearls lining its body
  • Pompom – A goldfish with nostrils that are enlarged and shaped like flowers
  • Ranchu – One of the dorsalless varieties of goldfish, with a wen covering its head and face
  • Ryukin – A relatively common breed with a hump shape behind the head and a pointed snout
  • Shubunkin – A calico-colored comet goldfish
  • Shukin – Prized for its long, flowing tail and smooth back (no dorsal fin)
  • Tamasaba – A Ryukin with a single tail
  • Tosakin – A twisted-tailed fish bred to be viewed from above, with a pointed snout
  • Veiltail – Also called broadtail, this fish has squared off, flowing fins
  • Wakin – Basically a double-tailed, long-tailed slim-bodied goldfish

Reproduction and Breeding

As the seasons change from the cold of winter to the warmth of spring, goldfish in ponds will spawn readily, if both genders are present.

(Breeding goldfish in captivity is trickier because of having to mimic so many natural factors.)

Are your goldfish spawning?

Chasing (a male goldfish aggressively nudging a female around the place) is a sure sign that spawning is going on.

They can easily lay up to 1,000 eggs at a time, and would eat them if given the opportunity!

The eggs are sticky and tend to get protected by plant matter as they sink to the bottom.

Once they hatch, the fry will eat off their yolk sacks for a few days until the time comes to scavenge for food.

It typically takes 9 months to a year for a goldfish to become full grown.


Male goldfish during breeding season will exhibit breeding stars on their gill covers and front fin rays, whereas females will swell with eggs and sometimes have a “lopsided” appearance.

Of course, chasing is a sign you have at least one male and female 🙂

Examining the anal vents of the fish is one way to tell, but you must have an experienced eye and even seasoned breeders make mistakes when it comes to telling whether their fish is a boy or a girl!

Health and Disease Issues

If you’ve ever tried to keep goldfish at any point in time, chances are you’ve run into problems with their health.

It’s true that goldfish are usually pretty hardy fish and have been known to survive the most extreme circumstances…

But they aren’t made of steel (not even the silver ones) 😉

Goldfish are living things, and like all people and most animals are definitely prone to infections of parasites, viruses and bad bacteria.

[Click here to learn more about some common (and not-so-common) goldfish diseases…]

They also can be negatively affected by their environment if the conditions aren’t exactly what they need.

Some symptoms of poor health can include lethargy, bloating, blood streaks on the fins, red patches, white patches, missing scales, scratching on objects, and much more. Ich is a common one for new goldfish.

[Click here for a complete list of symptoms…]

Pet stores unfortunately play a big role in the spread of disease due to the stress they place on fish during their importing and shipping process, which involves passing them through multiple intermediaries before they ever get to you.

Not only that, but there are lots of misconceptions around exactly what consists of proper care.

Bad care = bad health.

A big part of why goldfish come down with illness is actually because of all the misinformation given out by the pet stores themselves and by so-called “experts” online (who almost never agree with each other) – or even inaccurate books on the subject (and there are many).

I get this question a LOT:

“What is the best way to ensure your goldfish doesn’t get sick, or how do you bring a sick fish back to health?”

It all has to do with mastering the art of proper care and understanding exactly what to do in a crisis.

You can get all of the details on both of those in our book, The Truth About Goldfish.


It’s really sad because tons of goldfish die every single day due to diseases that are totally preventable and even treatable in many cases.

But because people don’t understand the needs of their pets, goldfish die much quicker than they should.

Most goldfish end up being kept in conditions they simply can’t survive in for long.

So they get a reputation for being short-lived creatures who can’t seem to live past a few months (if that).

But believe it or not:

With proper care, goldfish can live a very long time!

The oldest goldfish on record lived to the ripe old age of over 40 years old.

Fun fact:

You can tell how old a goldfish is by the microscopic rings they develop on their scales.

Diet & Feeding: What Do Goldfish Eat?

One thing goldfish have become famous for is their absolute gluttony.

They won’t stop eating for as long as you feed them – and in fact they will eat themselves to death!

This is because in the wild, goldfish are scavengers and foragers by nature.  Most of what they eat is rotting plant or insect matter (yuck!).

During times of plenty or scarcity, they have to eat whatever they can find to sustain themselves.  Obviously this doesn’t work so well in a closed aquarium with a sympathetic owner holding a huge jar of protein-packed, processed fish flakes!


Understanding the natural diet of goldfish is very important to their overall health.  They do need some protein, but it needs to be from a good source and in moderation.

That’s why it’s important to provide plenty of fibrous veggie matter to your goldies 🙂

Sadly, most commercial flake and pellet foods available at the pet store are just JUNK foods that give goldfish swim bladder problems and even fatty liver disease.

This is important:

Good things to feed your goldfish include live foods such as frozen bloodworms, brine shrimp and even earthworms from the garden.

Many goldfish kept in aquariums are overfed – you can often tell by their enlarged belly.

Overfeeding is not just dangerous to your goldfish’s health directly, but to the entire ecosystem of the tank.

Combine a dreaded goldfish bowl with an overfeeding owner and you’ve got a recipe for disaster! :O

[Want to learn more about feeding your goldfish? Check out this article.]

General Care and Housing

Your goldfish’s life resides in the hands of one person and one person alone:


How you take care of it will affect whether or not it lives a long, healthy, happy life – or a short and sickly one.

Their fate is in your hands!

Tank size

When it comes to picking out what kind of home your goldfish needs, it’s important to remember two things:

  • Goldfish grow much bigger than you think, especially the slim-bodied ones
  • Goldfish need adequate water volume and filtration in order to survive

Too often goldfish owners ignorantly keep their pets in a space that’s much too small and run into SO many problems as a consequence.

Let’s get this out of the way right now:

Goldfish bowls are terrible homes for these pets!

The picture of a goldfish swimming happily around in a glass bowl is downright false.

Bowls are bad for a TON of reasons.  Just don’t even think about it, okay? 😉

Instead, get your goldfish a properly sized tank and you will save yourself a lot of issues down the road.

[Click here to read what size tank a goldfish needs…]


You may have heard that goldfish are cold water fish and do not need a heater, but studies have shown that they do better in warmer waters (in the 70 degrees F range).

Natural fluctuations in temperature are normal…

… As long as they aren’t too drastic.

Sudden changes can shock and even kill a goldfish if they are too extreme.

It’s recommended not to change the water by 10 degrees at a time and monitor their health closely in the winter time if your fish live out in a pond.

This is just a short overview of care – obviously there is a LOT more to successful goldfish keeping than that 😉

[Click here to read our beginner’s setup guide…]

Purchasing & Collecting

I get this question a lot:

“Where should I get my goldfish?”

There are lots of options… but which one is the best?

I came up with a list of the most trustworthy sellers online to help answer that very question.

[View the full list here…]