The goldfish is a specific golden coloured type of lowland carp. The biology of the goldfish is well suited to still and slow waters. The lowland waters in which goldfish have traditionally existed are the types of environments where all manner of pollutants collect. It is the resulting evolved resilience of these fish that enables them to live in somewhat meagre conditions (such as a goldfish bowl) and enable them to thrive in the relatively luxurious surroundings of a garden pond.

The basic requirements of goldfish are essentially the same as for any fish. A need for food, oxygen and a reasonable quality of water. It is the broad spectrum of tolerable limits that make goldfish hardy and subsequently, so popular.

Providing the water temperature does not vary rapidly, goldfish will manage in a temperature range from below freezing to around 30ºC. A further advantage of goldfish is that they will manage with lower levels of dissolved oxygen than many other fish species.

The goldfish will be active from around March to October when the water has reached a temperature over 8ºC. The fish should be fed a small quantity many times a day and the use of colour enhancing foods should help to bring vibrant colours and markings to the fore.