GoldfishFamily: Cyprinidae Carassius auratus auratusPhoto © Animal-World: Courtesy David Brough
Goldfish are fun to watch... just look at all the different colors of these beautiful fish!
The Common Goldfish are colorful, inexpensive, and readily available. For about 90 percent of all aquarists, their first fish were Common Goldfish won at the local faire or obtained from the pet store in town. They can be quite personable and are delightful to watch.
One of the hardiest of the gold fish varieties, the Common Goldfish are recommended for beginners. They are an easy fish to keep as they are not picky and will readily eat what is offered. They are active and can swim fairly fast. They are also very social and thrive well in a community.
|Common Goldfish Comet Goldfish|
The Common Goldfish is very similar to, and sometimes confused with, the Comet Goldfish. The Comet Goldfish is a further development of the Common Goldfish. Both these fish have an almost identical body shape but the fins on the Comet are much longer, especially the caudal (tail) fin, and it is more deeply forked. Also, in the standard orange color the Comet is generally a more reddish orange while the Common Goldfish is more orangish. The adult size of the Comet Goldfish is smaller too. On both these fish the caudal (tail) fin is held fully erect.
Another goldfish that is almost identical to the Common Goldfish is the 'London' type of Shubunkin Goldfish. Both these fish have virtually the same body and fin shapes, but the London type Shubunkin Goldfish has a totally different body color. While a good specimen of the Common Goldfish will have a bright orange metallic color, this London type Shubunkin goldfish can be speckled or have a variegated color pattern.
Along with the other elongated goldfish, such as the Comet Goldfish and the Shubunkin Goldfish, Common Goldfish make good pond fish. They are hardy and can tolerate cold water temperatures. They are active and fast and can get along well with Koi, but they will readily spawn so can quickly overpopulate your pond.
For more goldfish information, see:
Goldfish Care: Fancy Goldfish and Goldfish Diseases
- Size of fish - inches: 14.0 inches (35.56 cm)
- Minimum Tank Size: 25 gal (95 L)
- Temperament: Peaceful
- Aquarium Hardiness: Very Hardy
- Temperature: 65.0 to 72.0° F (18.3 to 22.2° C)
- Aquarist Experience Level: Beginner
- My Aquarium - Enter your aquarium to see if this fish is compatible!
The goldfish of today are descendants of a wild carp fish, known as the Prussian Carp, Silver Prussian carp, or Gibel Carp Carassius gibelio (syn: Carassius auratus gibelio) which was described by Bloch in 1782. For many years it was believed that goldfish had originated from the Crucian Carp or Golden Carp Carassius auratus auratus described by Linnaeus in 1758, but more recent research is pointing toward the former. These wild carp originated in Asia; Central Asia (siberia). They inhabit the slow moving and stagnant waters of rivers, lakes, ponds, and ditches feeding on plants, detritus, small crustaceans, and insects.
In the early 1500's these fish were exported first to Japan and then to Europe and were developed into the wonderful colors and forms of gold fish we see today. The Common Goldfish is one of the more than 125 captive bred varieties that have been developed.
- Scientific Name: Carassius auratus auratus
- Social Grouping: Groups
- IUCN Red List: NE - Not Evaluated or not listed
The Common Goldfish is an elongated, flat-bodied variety of goldfish. The head is wide but short and it has a smoothly tapering body shape from its back and belly to the base of its caudal fin (tail fin). The caudal fin is forked. Its fins generally stand fully erect and the edge of the dorsal fin is slightly concave.
- Goldfish colors
The most distinguished specimen is a bright orange metallic color.
- Size - Weight
The environment the Common Goldfish is kept in is a determining factor on whether your pet grows to its full potential size or is somewhat smaller. In an average 10 gallon tank, if well cared for and not crowded, they can grow up to about 4 inches (10 cm), while in a larger uncrowded tank they can grow larger generally reaching about 7 or 8 inches (17.78 - 20.32 cm). If kept in a spacious pond they can reach over 12 inches (30+ cm), with some hobbyist reporting their Common Goldfish reaching up to a whopping 18" (45+ cm)!
- Goldfish lifespan
The average goldfish lifespan is 10 – 15 years, though living 20 years or more is not uncommon in well maintained goldfish aquariums and ponds.
- Size of fish - inches: 14.0 inches (35.56 cm) - In a pond this fish will grow much larger, if subjected to poor conditions and a small tank this fish will die young, stunted, and probably deformed.
- Lifespan: 20 years
Common Goldfish are some of the hardier species of goldfish. They are very undemanding of water quality and temperature. They can do well in goldfish aquariums, a pond, or even a goldfish bowl when small, as long as the environment is safe and their tank mates are not competitive.
Many people will keep goldfish in small one or two gallon goldfish bowls with no heater or filtration. But for the best success in keeping goldfish, provide them the same filtration, especially biological filtration, that other aquarium residents enjoy.
- Aquarium Hardiness: Very Hardy
- Aquarist Experience Level: Beginner
Since they are omnivorous, the Common Goldfish will generally eat all kinds of fresh, frozen, and flake foods. To keep a good balance give them a high quality flake food everyday. To care for your goldfish, feed brine shrimp (either live or frozen), blood worms, Daphnia, or tubifex worms as a treat. It is usually better to feed freeze-dried foods as opposed to live foods to avoid parasites and bacterial infections that could be present in live foods.
- Diet Type: Omnivore
- Flake Food: Yes
- Tablet Pellet: Yes
- Live foods (fishes, shrimps, worms): Some of Diet
- Vegetable Food: Some of Diet
- Meaty Food: Some of Diet
- Feeding Frequency: Several feedings per day
Regular weekly water changes of 1/4 to 1/3 is strongly recommended to keep these fish healthy. Snails can be added as they reduce the algae in the tank, helping to keep it clean.
- Water Changes: Weekly
Setting up an aquarium in a manner that will keep your fish happy and healthy is the first step to successfully fish keeping. Here are aquarium parameters to consider in choosing goldfish aquariums, filtration, lighting, and decor as well as temperature and water movement.
- Minimum Tank Size / Length:
The shape and size of the goldfish aquarium is important and depends upon the number of fish you are going to keep. Goldfish need a lot of oxygen and produce a lot of waste. Keep the tank size and shape in mind when you are buying your fish.
- Tank Shape
A large surface area of water will help minimize goldfish suffering from an oxygen shortage. Surface area is determined by the shape of the tank. For the same volume of water, an elongated tank offers more surface area (and oxygen) than a tall tank. In a goldfish bowl, filling the bowl to the middle offers more surface area than filling the bowl to the top. Always provide the maximum amount of surface area.
- Tank size
It's best to start with a 20 - 30 gallon tank for your first goldfish and then increase the size of the tank by 10 gallons for each additional goldfish. Providing a large amount of water per fish will help dilute the amount of waste and reduce the number of water changes needed
- Formula: # of fish per gallon of water
A general rule of thumb, but only for young fish, is 1 inch of fish (2.54 cm) per 1 gallon of water. This rule applies only to young fish and is not adequate as they grow. Larger gold fish consume much more oxygen than young fish so maintaining this formula for growing fish will stunt them, and can contribute to disease and even death.
- Fish: size and growth
To allow for growth, either buy fewer fish than the maximum number of fish (based on the formula above) or be prepared to get a larger tank. Larger gold fish consume much more oxygen than young fish so maintaining this formula for growing fish will stunt them, and can contribute to disease and even death
- Tank Shape
- Aquarium Lighting
Most aquariums come with a cover that includes lighting. A cover for the tank is desirable as it reduces evaporation and though they are not prone to jumping, on occasion some gold fish will jump out. Lighting is not essential for goldfish, but does make the aquarium a nice show piece and lighting will help if you have live plants.
Goldfish produce a lot of waste. Good filtration, especially biological filtration, is very helpful in maintaining the water quality of the aquarium. Filtration systems remove much of the detritus, excess foods and waste. This helps keep the tank clean and maintain the general health of the goldfish.
Provide a gravel substrate to help create a natural and comfortable environment for your fish. A medium sized gravel works best..
- Aquarium Decor
You can add some decor, but make sure that all ornamentation is smooth with no protruding points or sharp edges. Smooth rocks or driftwood, should be used sparingly if at all.
Aquarium plants would be the best choice of aquarium decor for goldfish, but unfortunately these fish are diggers. Consequently live plants may be uprooted. Artificial plants make a good substitute and silk plants are safer than plastic ones.
- Temperature: Goldfish are a cold water fish and will do best at temperatures between 65 - 72° F (18°- 22° C). The Common Goldfish is one of the most hardy varieties of goldfish and can tolerate temperatures a few degrees above freezing, as long as the cooling drops only a few degrees a day. A quick temperature drop can kill them, so if you live in a very cold climate a heater is advisable.
- Water Hardness: 5 - 19° dGH
- ph: 6.0 to 8.0
- Water Movement: Moderate.
- Water Region: These fish will swim in all areas of the aquarium.
- Minimum Tank Size: 25 gal (95 L) - This fish can grow to over a foot in length, keeping it in a small tank will horribly stunt its growth and cause irreversible damage. 25 gallons is really the absolute minimum suggested for this variety of Goldfish.
- Substrate Type: Any
- Lighting Needs: Moderate - normal lighting
- Temperature: 65.0 to 72.0° F (18.3 to 22.2° C)
- Range ph: 6.0-8.0
- Hardness Range: 5 - 19 dGH
- Brackish: Sometimes - Goldfish are freshwater fish, but they have some tolerance for slightly brackish water. Yet any salinity for C. auratus must be kept below 10%, a specific gravity of less than 1.002.
- Water Movement: Moderate
- Water Region: All
Goldfish are very social animals and thrive in a community. Not only are they a great community fish but they are great scavengers as well. It is really not necessary to add other scavengers or other bottom feeders to the aquarium when you have goldfish.
Most fancy goldfish will thrive in both freshwater and tropical aquariums as long as there are no aggressive or territorial fish in the tank. Some good tank mates for fancy goldfish are the Chinese Blue Bitterling and the Northern Redbelly Dace.
Common Goldfish can be kept with other varieties of elongated goldfish, such as the Comet Goldfish and the Shubunkin, and they also do fine with Koi.
- Venomous: No
- Temperament: Peaceful - This fish is active and friendly.
- Compatible with:
- Same species - conspecifics: Yes
- Peaceful fish (): Safe
- Semi-Aggressive (): Threat
- Shrimps, Crabs, Snails: Safe - not aggressive
- Plants: Threat - Goldfish produce more waste than most other freshwater fish and benefit greatly from more frequent water changes.
Although is it impossible to sex Goldfish when they are young and not in breeding season, the male is usually smaller and more slender that the female. In the breeding season the male has white prickles, called breeding tubercles, on its gill covers and head. Seen from above the female will have a fatter appearance as she is carrying eggs.
Common Goldfish are egg layers that spawn readily in the right conditions. See Breeding Freshwater Fish - Goldfish for more information on breeding Goldfish.
- Ease of Breeding: Easy
Goldfish are subject to the same diseases as tropical fish. A couple of the more common problems are Ich, Swim Bladder Disease, and external parasites including flukes, lice and anchor worms. For more in-depth information about goldfish diseases and illnesses, see: Goldfish Care; Fancy Goldfish and Goldfish Diseases.
The Common Goldfish is readily available in fish stores and on-line, and is inexpensive
- Animal-World References: Freshwater Fish and Plants
- David Alderton, Encyclopedia of Aquarium and Pond Fish , DK Publishing, Inc., 2005.
- Marshall E. Ostrow, Goldfish (Barron's Complete Pet Owner's Manuals), Barron's Educational Series, Inc. 2003
- Geoff Rogers, Nick Fletcher, Focus on Freshwater Aquarium Fish, Firefly Books. 2004
- David Sands, Goldfish (Caring for Your Pet), Interpet Publishing, 1999