The goldfish
The goldfish is a classic fish for the garden pond. A member of the carpe family, it is an easy fish to manage in temperate regions as it supports progressive changes in temperature, whether it is very hot or very cold.
The goldfish has its origins in China, where it has been bred regularly and selectively for over a thousand years. At first it was a rather dull-coloured Asian carpe, but has become coloured due to cross-breeding and hybridization.
It came to France in the 17th. Century when it was offered to the French court by visiting Chinese traders.
A member of the Cyprinidae family, it is a close cousin of the carpe, but is a lot smaller, making it suitable for small garden ponds or indoor aquariums.
Like the carpe, many different varieties exist. The most common variety has a stocky, compact body and is entirely reddish orange in colou. It generally measures no more than 25 cms. in the aquarium, but can grow up to 40 cms. in an outdoor pond.
All these varieties reproduce easily in outdoor ponds, and with more difficulty in aquariums due to the promiscuity and voracity of the adults.
The goldfish is very resistant to changes in temperature and can easily support a temperature of -10°C outdoors, on condition that the change is gradual. Likewise, once the change is not too abrupt, it can adapt to very hot weather.
The same cannot be said for the variety of goldfish called "sail-tails" or comet which don't survive big changes in temperature outdoors !
Many other varieties have been created over the centuries, some of which bear no resemblance to their origins ! Among the the wierdest ones are the lion-headed goldfish which have bulges on the top of their heads, telescopic goldfish with their protruding eyes, and the shubukin which have dorsal gills and very long tails. Reddish orange is the classic colour of goldfish, but many species have different mixtures of colours : red and white, bronze and white, deep black, etc...
They generally live between 5 to 10 years in an aquarium and often up to 15 years in an outdoor pond. They continue to grow until their death.