TankBud

Variety of Goldfish

Comet

Carassius auratus

One of 12 varieties of Carassius auratus · See all varieties →

Also known as Comet-tailed goldfish, Sarasa comet

FreshwaterFish

Comet (Carassius auratus)
Oldhag · Public domain

Varieties · Carassius auratus

See all 12 →

Care at a glance

Temperature
39–75°F
4–24°C
pH
6.5–8.0
Adult size
11.8 in
30 cm
Minimum tank
50 gal
190 L
Temperament
Peaceful
Social behavior
Social
Tankmates
With caution
Swim level
Middle
Diet
Omnivore
Difficulty
Easy
Breeding
Egg scatterer · Medium
Rarity
Very common
Family
Cyprinidae
Origin
A hardy single tailed pond goldfish developed in the United States from common goldfish, a domesticated form of Carassius auratus native to East Asian freshwater.

Overview

The comet is a slim, fast and very hardy single-tailed goldfish with a long, deeply forked tail. It is easy to keep, given a pond or a large tank.

Did you know

Comets given pond space and years of growth routinely reach 25 to 30 cm. That is far larger than the fish most people picture from a fair prize bowl.

Caring for the comet

Comets grow large and fast, so keep them in a pond or a tank of at least 50 gal (190 L). Add much more space for each extra fish. No goldfish belongs in a bowl.

Like the common goldfish, a comet tolerates a wide temperature range and can overwinter in an outdoor pond. It handles 39 to 75°F (4 to 24°C) at a pH of 6.5 to 8.0. Its heavy waste calls for strong filtration.

Feed a good goldfish pellet, with vegetables and occasional live or frozen treats. A goldfish has no stomach, so food passes through it quickly.

Comets are peaceful and social, and each one wants the company of its own kind. Keep them with other single-tailed goldfish, never with slow fancies. A comet is a prolific egg scatterer and spawns readily in ponds each spring.

Good to know

The comet is the same species as all other goldfish, Carassius auratus, a member of the family Cyprinidae. It keeps the wild body's strength and cold tolerance. The popular red and white form is sold as the sarasa comet.

In the wild

The comet was bred in the United States in the 1880s from common goldfish, selected for a longer, flowing single tail. The common goldfish is a domesticated form of Carassius auratus, native to freshwater in East Asia.

From published sources

Tank mates

Each fish here is named as a tank mate for the comet by at least two published care guides. Every partner here handles cool water. The tank needs about 20 gallons (75 liters) for the first fancy goldfish and 10 gallons (38 liters) for each extra one.

Sources: Practical Fishkeeping, Aquarium Co-Op, Fishkeeping World, Aquarium Source, Tropical Fish Hobbyist.

Check the full mix in the stocking calculator

Common questions

Is a comet a different species from the goldfish?

No. A comet is a variety of the goldfish, Carassius auratus. It is kept the same way apart from difficulty, adult size, tank size and temperature.

What size tank does a comet need?

A comet needs at least 50 gal (190 L). It spends most of its time in the middle.

What does a comet eat?

A comet eats a good goldfish pellet, with vegetables and occasional live or frozen treats.

How big does a comet get?

An adult comet reaches about 11.8 in (30 cm).

How does a comet breed?

A comet is a prolific egg scatterer. It spawns readily in ponds each spring.

What fish can live with the comet?

Published care guides name weather loach, bristlenose pleco, bulldog pleco and variable platy, among others. Every partner here handles cool water. The tank needs about 20 gallons (75 liters) for the first fancy goldfish and 10 gallons (38 liters) for each extra one.

Related species