Background
Pet fish can consist of a wide variety of species but can be grouped according to whether they are fresh water or marine and cold water or tropical.
The coldwater species are usually easier to keep, whether in a back garden pond or in an indoor aquarium. They include goldfish which were one of the earliest fish to be domesticated and are one of the most common aquarium and pond kept fish, koi carp, shubunkins and orfe.
Tropical fresh water fish include the colourful tetras and gouramis, whilst the most popular marine fish are the clown fish (popularised as Nemo in the childrens’ film).
The size of ornamental pet fish can vary dramatically from a couple of cm in length to in excess of half a metre for some of the more mature koi carp.
Lifespan
The lifespan of pet ornamental fish varies widely between species, and it pays to research the type you wish to keep to make sure you don’t run into potential problems either with the disappointment of short-lived specimens to problems at the other end of the scale with some coldwater fish such as koi carp which can live in excess of 60 years. In fact the oldest recorded koi was about 226 years old and lived in a back garden pond in Japan, and was passed down from generation to generation.
