Goldfish Info

All good goldfish keepers take the time to learn about their pets. Knowing more about goldfish helps us to take better care of them.

Why not start by learning the 12 mistakes most new goldfish-keepers make?

You can also explore diseases, like swim bladder disease, and learn how to prevent them.

Plus, do you know the difference between goldfish and koi? Where goldfish come from? And whether or not they have tongues?!

Our Goldfish Facts & Info articles are where you can learn all of this and much more about your goldfish.

Goldfish and leeches

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Cartoon of a goldfish with leeches

Leeches are not among the most common of goldfish parasites, but nevertheless, they are rather nasty, and easily introduced into an existing tank.

Leeches live by latching onto a living host (such as a goldfish) and feasting on the blood of the host, before detaching and dropping away when they are full, and then repeating the process every time that they are hungry.

Understandably, leeches can pose a health hazard to goldfish, both through blood loss and through the risk of infection to the abrasions left behind after they detach from the skin.

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The Difference between Koi and Goldfish: Are Goldfish Carp?

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Are Goldfish Carp

Have you ever wondered whether goldfish and koi are the same type of fish? And whether they could breed with each other?

Do you struggle to tell koi and goldfish apart?

While they are related, the two types of fish are actually different species, with many differences between them.

Read on to learn more about these differences. We’ll start by looking at the different origins of the two types of fish, then look at their physical differences. Finally, we’ll find out whether koi and goldfish can breed with each other.

Takeaways:

  1. Koi vs Goldfish: While both are types of carp, koi and goldfish belong to different species and genera. Koi are a subspecies of the common carp, while goldfish are from a different genus.
  2. Origins: Koi were first bred in Japan in the 1820s, while goldfish originated in China over a thousand years ago. Both were selectively bred for attractive colors and patterns.
  3. Taxonomy: Koi belong to the genus Cyprinus, while goldfish belong to Carassius. This separation happened millions of years ago.
  4. Physical Differences: Koi are larger, have barbels near their mouths, and have an attached dorsal fin. Goldfish are smaller, have varied body shapes, and a split caudal fin.
  5. Breeding: Goldfish and koi can breed with each other, but the resulting offspring are sterile, meaning they can’t reproduce.
  6. Living Together: Koi and goldfish can live together, but koi tend to outcompete goldfish for food and space due to their size and strength.

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Goldfish and constipation

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Cartoon of a goldfish with a big belly due to constipation

All fish can potentially suffer from constipation, regardless of the type of diet they are fed, and goldfish are no exception. As goldfish are prolific eaters, constipation is one of the more common problems they face.

So, if you’re wondering how to tell if your goldfish is constipated – and what you should do about it if so – then read on to learn more about constipation in goldfish.

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Where do goldfish come from?

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Cartoon of a goldfish looking at a world map

Have you ever thought about where goldfish come from? You might have picked them up from the pet store, but how did they get there?

Why did people start keeping goldfish as pets? And where do pet stores get the millions of goldies that are sold every year?

There’s a fascinating story behind the first pet goldfish and, if you haven’t heard it before, you’ll never guess how it happened!

Read on to find out more.

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Goldfish and ulcers

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Cartoon of a goldfish with an ulcer

Ulcers in goldfish can be caused by a range of different diseases, but they are almost exclusively bacterial in nature.

The two most common types of bacterial goldfish ulcers are Aeronores and Pseudomonas. However, as the treatment of bacterial goldfish ulcers are the same regardless of the bacterial strain responsible, in this article we will simply refer to them as “ulcers” rather than drawing the distinction between different strains.

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Decoding goldfish behavior

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Cartoon of two goldfish chasing each other

If you keep pet goldfish, you have almost certainly spent many hours watching them go about their daily lives, interacting with their surroundings and each other, and doing all of the normal things that goldfish do!

But have you ever watched your goldfish swimming around and wondered exactly why they are doing what they are doing, or what their behavior means? Many of us have!

Goldfish are generally thought of as being fairly simple creatures, and the different behaviors that they exhibit are not difficult to interpret, if you know what you are looking for. Read on to learn about how to decode some of the most common pet goldfish behaviors.

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