Telescope Goldfish
Demekin, Dragon Eye Goldfish, Globe Eye Goldfish
Family: Cyprinidae
Calico Telescope GoldfishCarassius auratus auratusPhoto © Animal-World: Courtesy TammyThe Telescope Goldfish is a bizarre looking fish, with eyes perched on stalks sticking out from its head!
The eyes are a most curious characteristic of the Telescope Goldfish.Their large eyes are set on top of long telescope or cone-like stalks mounted on the sides of its head. On some fish these stalks can extend out as far as 3/4 of an inch (19 - 20 cm), but they don't really start to protrude until these fish are about 6 months old. It is believed the Telescope Goldfish were first developed in China in the early 1700's and were called the Dragon Eye Goldfish or Dragonfish. Later in that century they were produced in Japan and were given the name Demekin, which the Japanese still call them today.
Rather than having the long slender body of the Common Goldfish or the Shubunkins, this is one of the more rounded or egg-shaped fancy gold fish. Other than its eyes, and being slightly smaller, a basic Telescope Goldfish is very similar to the Fantail Goldfish. The body is short and stubby, the head is very wide, and they have a split caudal fin (tail fin) that is moderate in length and slightly forked.
Today they are also available with long flowing fins and a couple other tail fin styles: veil tail, broadtail, and butterfly tail. There are many different colors in both metallic and nacreous scale types, but seldom in a matte scale type. These include solids of red, blue, chocolate, or white; tri-colored and calico; and bi-colored versions in red/white and black/white. The bi-colored black/white version is affectionately known as the Panda Telescope Goldfish and there is a unique chocolate version with orange pompoms. The well known, and very popular Black Moor Goldfish is basically a black version of the Telescope Goldfish though its eyes don't protrude quite as far.
Like the Black Moor the Telescope Goldfish have the ability to live at colder temperatures, but unlike their cousin they are not considered a good beginner fish. This is not because they lack general hardiness, but rather because of their more extremely telescopic eyes. Their eyes cause them to have poor vision so they are not a good competitor for food, and their eyes are subject to injury and infection. These fish will thrive best housed with the other similarly handicapped including the Black Moor and the less hardy Bubble Eye Goldfish Lionhead Goldfish, and Celestial Goldfish.
For more goldfish information, see:
Goldfish Care: Fancy Goldfish and Goldfish Diseases
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- Temperament: Peaceful
- Aquarium Hardiness: Moderately hardy
- Aquarist Experience Level: Beginner
- Diet Type: Omnivore
- Minimum Tank Size: 10 gal (38 L)
- Temperature: 65.0 to 72.0° F (18.3 to 22.2° C)
- Range ph: 6.0-8.0
- Hardness Range: 5 - 19 dGH
- My Aquarium - Enter your aquarium to see if this fish is compatible!
- Beginner Fish - Freshwater fish for beginners
- Community Fish - Peaceful Freshwater fish
- Hardy Fish - Hardy Freshwater fish
- Similar size fish - Fish that are 1 inch bigger or smaller
- Coldwater Fish - Looking for cold water fish? (65 °)
Habitat: Distribution / Background
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. 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. 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.
Goldfish were originally developed in China, but by the 1500's goldfish were traded to Japan, to Europe in the 1600's, and to America by the 1800's. The majority of the fancy goldfish were being developed by Oriental breeders. The results of this centuries long endeavor is the wonderful goldfish colors and forms we see today. Today domesticated goldfish are distributed world-wide.
The Telescope Goldfish is also known as the Demekin, Dragon Eye Goldfish, and Globe Eye Goldfish. It was believed to be developed in China in the early 1700's where it was known as the Dragon Eyes or the Dragonfish. In the later part of the 1700's it was produced in Japan where it is known as the Demekin. The Black Moor is still referred to as the Dragon Eye Goldfish as well as the Black Demekin. Today there are more than 125 captive bred fancy gold fish varieties.
- Scientific Name: Carassius auratus auratus
- Social Grouping: Groups
- IUCN Red List: NE - Not Evaluated or not listed - There are no wild populations of this captive bred variety.
The Telescope Goldfish is an egg-shaped variety of goldfish. Other than its eyes, and being slightly smaller, a basic Telescope Goldfish is very similar to the Fantail Goldfish. The body is short and stubby, the head is very wide, and they have a split caudal fin (tail fin) that is moderate in length and slightly forked.
Their large eyes are set on top of long telescope or cone-like stalks mounted on the sides of its head. On some fish these stalks can extend out as far as 3/4 of an inch (19 - 20 cm), but they don't really start to protrude until these fish are about 6 months old. Today the Telescope Goldfish are also available with long flowing fins and a couple other tail fin styles: veil tail, broadtail, and butterfly.
The bi-colored black/white version is affectionately known as the Panda Telescope Goldfish and there is a unique chocolate version with orange pompoms. The well known, and very popular Black Moor Goldfish is basically a black version of the Telescope Goldfish though its eyes don't protrude quite as far.
- Goldfish colors
There are many different colors in both metallic and nacreous scale types, but seldom in a matte scale type. These include solids of red, blue, chocolate, or white; tri-colored and calico; and bi-colored fish in red/white and black/white. - Size - Weight
Telescope Goldfish will generally reach about 4 inches (10 cm), though they have been known to grow much larger in many aquarists tanks. - 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: 8.0 inches (20.32 cm) - Telescope Goldfish rarely exceed five inches in the home aquarium, however given optimal conditions they can grow up to eight inches in length.
The Telescope Goldfish are not considered a good beginner fish. This is not because they lack general hardiness, but rather because of their more extremely telescopic eyes. Besides causing them to have poor vision, their eyes are subject to injury and infection. They are very undemanding of water quality and temperature. They can do well in a goldfish bowl, an aquarium, or even a pond if the environment is safe, well maintained, and have tank mates that are not competitive. When it comes to feeding, they will not thrive well with fast competitive tank mates.
Many people will keep goldfish in small one or two gallon 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. Be careful when netting these fish, as their eyes are easily damaged. When it comes to feeding, they will not thrive well with fast competitive tank mates.
- Aquarium Hardiness: Moderately hardy
- Aquarist Experience Level: Beginner
Since they are omnivorous, the Telescope 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. 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. Due to the protruding eyes they have poor vision and a harder time seeing their food, so need extra time to feed.
- 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 - This fish has poor vision and is a poor swimmer and as such might easily be outcompeted for food by swifter moving tankmates.
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. - Filtration
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. - Substrate
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 keep in mind that the eyes of the Black Moor are a handicap and these fish have very poor vision. 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 Telescope Goldfish 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: 10 gal (38 L) - Ten gallons is the absolute minimum required to house this fish. It has high oxygen requirements, produces a lot of waste, and will have very stunted growth if it is kept in a smaller aquarium or bowl.
- Suitable for Nano Tank: Sometimes
- 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. The Telescope Goldfish, along with the Black Moor Goldfish, Bubble Eye Goldfish, and the Celestial Goldfish, are all visually handicapped. They cannot readily compete for food with other types of goldfish so may not fare well if housed with them, but they will do well housed together. Goldfish are great scavengers, so it is really not necessary to add other scavengers or other bottom feeders to the aquarium when you have goldfish.
- Venomous: No
- Temperament: Peaceful
- Compatible with:
- Same species - conspecifics: Yes
- Peaceful fish (): Safe
- Semi-Aggressive (): Threat
- Shrimps, Crabs, Snails: Safe - not aggressive
- Plants: Threat - Goldfish will eat many kinds of aquatic plants, and their constant search for food can end up uprooting plants that they don't eat.
During the breeding season the male has white prickles, called breeding tubercles, on its gill covers and head. Seen from above a female will have a fatter appearance when she is carrying eggs. It is impossible to sex Goldfish when they are young and not in breeding season, but generally the male is smaller and more slender than the female.
Telescope 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: Moderate
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 Telescope Goldfish is readily available in fish stores and on-line, and is fairly 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
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