Goldfish

Care at a glance

Overview

Goldfish are hardy, peaceful coldwater fish that come in two bands, the fast single-tails and the round-bodied fancies. The common, comet and shubunkin are single-tails, while the oranda, ryukin and ranchu are fancies that stay smaller. Pick a variety below for its own numbers.

Caring for the goldfish

No goldfish belongs in a bowl. Goldfish grow bigger, live longer and make more waste than most people expect. Single-tails are fast and belong in a pond or a very large tank. Fancies need 75 to 114 L per fish with strong filtration.

A goldfish has no stomach, so food passes through quickly. A well fed goldfish produces a lot of ammonia, which is the reason behind the big-tank, big-filter advice.

Every variety is a coldwater fish that wants a pH of 6.5 to 8.0 and room to swim. Fancies want warmer, calmer water and are most comfortable at 59 to 75°F (15 to 24°C). Single-tails handle 39 to 75°F (4 to 24°C).

Feed a varied diet of pellets, vegetables and the odd frozen food. Goldfish are peaceful and social, and every variety wants the company of its own kind.

Goldfish were domesticated from a wild, silver-brown carp in China roughly a thousand years ago, and every variety since has come from selecting body, tail, eye and head mutations within the same species. A comet and a bubble eye are as closely related as two littermates; the differences are entirely bred, which is why the bands differ in what they can live in but not in what they are.

Fancy varieties mix well with each other: they swim at the same slow pace and compete evenly for food. Keep single-tails with single-tails. They are faster, take the food first, and need colder water and far more space than a fancy setup provides. The delicate-eyed forms, bubble eye, celestial eye and black moor, do best with equally slow tank mates and nothing sharp in the tank.

Good to know

Carassius auratus is a cyprinid, a member of the carp family. Its wild ancestor is still argued over. One leading candidate is the Prussian carp, Carassius gibelio, and another is a wild form of Carassius auratus itself. Goldfish live 10 to 15 years with good care and far longer in ponds. They can see into the ultraviolet, and their color comes from pigment in the scales and skin. That color can shift with light, diet and age.

In the wild

The goldfish's wild carp ancestor comes from eastern Asia, where it lives in slow rivers, lakes and ponds in China. Early keepers held yellow and orange mutants of the wild fish in ponds and later in bowls. The goldfish reached Japan in the 1500s and Europe in the 1600s. Released goldfish revert to the wild color within a few generations. They now live feral on every continent except Antarctica, growing large and muddying the water, so never let one go.

Common questions

Related species

• 

  Crucian carp

  Carassius carassius

  11.8 in (30 cm) · 119 gal (450 L)

  11.8 in (30 cm)119 gal (450 L)39–75°F (4–24°C)

• 

  Ablabes barb

  Enteromius ablabes

  3.1 in (8 cm) · 24 gal (90 L)

  3.1 in (8 cm)24 gal (90 L)72–81°F (22–27°C)

• 

  African banded barb

  Barbus fasciolatus

  2.4 in (6 cm) · 20 gal (75 L)

  2.4 in (6 cm)20 gal (75 L)68–79°F (20–26°C)

• 

  African butterfly barb

  Barbus hulstaerti

  1.4 in (3.5 cm) · 11 gal (40 L)

  1.4 in (3.5 cm)11 gal (40 L)63–75°F (17–24°C)

• 

  Apsara barb

  Dawkinsia apsara

  3.5 in (9 cm) · 42 gal (160 L)

  3.5 in (9 cm)42 gal (160 L)70–79°F (21–26°C)

• 

  Arulius barb

  Dawkinsia arulius

  4.7 in (12 cm) · 37 gal (140 L)

  4.7 in (12 cm)37 gal (140 L)66–77°F (19–25°C)