SPCA New Zealand
Advice & welfare

Debunking goldfish myths

The humble goldfish tends to be misunderstood. They make great family pets, but they are plagued by myths that insult their intelligence, and individual personalities.

We’re busting these myths: read on to find out the truth about our finned friends!

Myth 1 - Goldfish Have a 3-Second-Memory

It has long been said goldfish have a 3-second-memory and don’t get bored. There is a common joke that by the time a goldfish has circled a bowl, it has forgotten doing so. However, the truth is quite the opposite! Goldfish have a memory span that lasts quite a long time.

Goldfish can hold memories for up to five months, and have a sense of time and routine. If you are a goldfish owner, you might notice they get excited in the morning before you get the food container out. There are even reports of goldfish repeatedly jumping out of the water out of sheer excitement when they see their owner walking through the door.

Myth 2 - Goldfish Only Grow to the Size of their Enclosure

There is an element of truth to this myth. But what really stunts their growth is poor water quality associated with a small tank, rather than the tank size itself. When properly cared for, goldfish never stop growing. The ‘common goldfish’ are the largest kind of goldfish and can grow up to 45cm long.

Stunted growth is a sign of sickness, and as a result goldfish can die prematurely. To avoid this and keep your fishy friend healthy, the recommended tank length for the ‘common goldfish’ should be at least 120cm long, or a minimum of 112L per adult goldfish.

‘Fancy goldfish’ can thrive in a tank that is at least 90cm long, and 75L per adult goldfish.

If you plan to keep more than one goldfish in your tank, then add an extra 40L for each additional fish – but if you want to see them reach their full potential, the bigger the better!

But if you only have space for a small tank, it is best to consider some small tropical fish, there are a number of species which don’t grow very large and have beautiful colours which light up your tank!

Myth 3 - Goldfish can be kept in Bowls

Although goldfish are hardy fish capable of surviving in a range of conditions, a bowl is not an ideal home.

Goldfish create a lot of waste, tend to be very messy, and eat a lot. They need an aquarium with proper filtration, aeration, water volume for dilution of waste, room to grow, and a home for good bacteria to mature.

The ‘common goldfish’ grow particularly big, so an outdoor pond is the best option unless you can provide them with an aquarium which can hold 200 litres or more.

These quirky and wonderful creatures deserve a home that’s as beautiful as them.

Myth 4 - Goldfish don’t live long

In fact, the opposite is true! Goldfish are some of the longest living fish you can adopt. They are able to live for several decades when well looked after – the record is held by a 49 year old goldfish!

It is possible this myth came about because of goldfish dying prematurely due to poor conditions in which they are kept, rather than the actual lifespan of the fish.

Myth 5 - There is only one type of goldfish

There are many different varieties of goldfish. The common goldfish you see are fantails, lion heads, ryukins, comets, orandas, bubble eyes, and commons.

They generally tend to fall into two main groups: hardy goldfish, and fancy goldfish. Hardy goldfish are slim bodied and have a single tail, whereas fancy goldfish have an egg shaped body and twin tails.

It’s best not to have hardy goldfish and fancy goldfish living in the same aquarium as hardy goldfish are faster moving, dominate the access to food, and tend to bully the fancy goldfish. You want to avoid playground arguments at all costs!

If you are thinking of creating a multi-fish palace, remember that if your goldfish is large enough to swallow another fish, he probably will.

Myth 6 - Goldfish tanks should have cold water

Goldfish are capable of surviving in both cold and warm conditions, but room temperature between 18-21 degrees is best. When temperatures are above 23 degrees, goldfish can also become lethargic and over heat. If you have higher temperatures in your goldfish tank, make sure you have vigorous aeration.

Goldfish can survive in water that is frozen on top. However this is not ideal, and a hole should be kept free of ice on the surface. During the winter if you are wondering why your goldfish isn’t moving around much, chances are your goldfish is cold! When temperatures are below 16 degrees, goldfish can slow down, stop eating, and hover at the bottom of the tank or pond.

If you see your goldfish exhibiting these symptoms, it may be time to invest in an aquarium heater to keep the water temperatures moderate and stable.

Myth 7 - Goldfish are Herbivores

Goldfish are actually omnivores, and eat both plant and animal material. A high quality goldfish pellet should be their staple diet for a goldfish but you can also vary their diet by giving them additional fresh food. This can include plant material such as romaine lettuce, peas (with the shells removed), cucumber, oranges, and soft-leaved aquarium plants such as duckweed and anacharis.

In the wild goldfish would eat fish eggs, invertebrates, and smaller fish species. Frozen invertebrates are a delicious treat for goldfish!

Hello! Choose your nearest SPCA Centre and see content specific to your location:
Hit enter to submit