10 Interesting facts about goldfish


DIY and how-to

A goldfish with vibrant orange scales and yellow fins swimming in a dark fish tank.

Goldfish are amazing beginner fish. They are found in pet shops in most of the world.

Goldfish and Koi are both members of the carp family, but they differ from each other in that goldfish lack any barbels around the mouth.

Goldfish are suitable for both ponds and home aquariums, although the very fancy types vary in terms of their hardiness, and are not all suited to being kept outdoors all year.

Goldfish are available in many sizes, shapes and colours. There are actually over 125 varieties of goldfish.

What are the most popular types of goldfish?

  • Common goldfish
  • Comet goldfish
  • Fantail goldfish
  • Shubunkin goldfish
  • Ryukin goldfish
  • Bubble-eye goldfish
  • Lionhead goldfish
  • Ranchu goldfish
  • Pearlscale goldfish
  • Veil tail goldfish
  • Black moor goldfish
  • Oranda goldfish

Types of Goldfish:

There are two main types of goldfish: the egg-shaped goldfish and the flat body type. The flat body goldfish generally are the hardiest, most competitive and easiest to care for – thus they are most suited for beginners. Flat body type goldfish include the Common, Comet, Wakin, Jikin and Shubunkin goldfish. Egg-shaped goldfish include the Fantail, Ryukin, Veiltail, Oranda, Pearlscale, Telescope-eyed, Black moor, Ranchu and Bubble-eye. It is important to note that most egg-shaped goldfish, with the exception of the Fantail, Ryukin, and Black moor, are not suited to be kept in an outdoor environment such as a pond.

Goldfish and Koi are sometimes referred to as coldwater fish, which just means they can survive in an unheated aquarium. Even though they are coldwater fish, this does not imply that they can tolerate very rapid fluctuations in water temperatures. Temperatures below 10 °C are dangerous to fancy goldfish varieties and can increase their chances of becoming sick and ill.  During winter months, goldfish will become sluggish, stop eating, and often stay on the bottom of the pond. This is completely normal behavior; once the temperature is warmer they will become active again.

Although goldfish bowls are very popular, they are not an ideal environment to keep goldfish. Goldfish are very easy to care for, but they still require cleaned and well-aerated water, which is hard to maintain in a goldfish bowl. Housing a goldfish in a bowl can increase the risk of nitrate/ammonia poisoning and stunting the goldfish.

What do Goldfish eat?

Goldfish will consume almost anything. The kind of food goldfish will eat includes flakes, cooked peas and insect larvae. Flake food often is preferred over pellet food due to the fact that it is easier for the goldfish to see and to clean up afterwards.

How long do Goldfish live?

In general the lifespan of goldfish is over 10 years. Goldfish can show a range of social behaviour. When new fish are introduced to an aquarium, aggressive “bully-like” social behaviours may sometimes become evident, such as chasing the new fish, or fin nipping. Goldfish lay eggs. They produce adhesive eggs that attach to aquatic vegetation. The eggs usually hatch in three to five days when temperatures are kept around 18 to 23 °C.