Telescope Eye Goldfish Guide – Master The Care Of This Majestic Fancy
The telescope eye goldfish is a unique fancy variety characterized by its protruding eyes and egg-shaped body. Successful care involves maintaining pristine water quality, providing gentle filtration, and ensuring a safe tank environment free of sharp decor.
In my twelve years of keeping fancy goldfish, few sights are as captivating as a group of Demekin—the Japanese name for these wonderful creatures—gliding through a well-maintained tank. Their wobbling swim style and expressive, enlarged eyes make them a favorite among hobbyists, but they do require a specific approach to thrive.
When I first started keeping these fish, I learned quickly that they aren’t your average “feeder” fish; they are a specialized breed of Carassius auratus that demands attention to detail. This telescope eye goldfish guide is designed to help you navigate those details, from water chemistry to physical safety.
Whether you are a beginner looking for your first “fancy” or an intermediate keeper refining your technique, understanding the biological needs of these fish is the first step toward a long-lived pet. Let’s dive into the world of these telescopic wonders and ensure your aquarium is a sanctuary rather than a hazard.
Understanding the Unique Biology of the Demekin
The most striking feature of the telescope goldfish is, of course, its eyes, a condition known as Exophthalmia. These eyes usually begin to “pop” or protrude when the fish is about six months old, eventually becoming the defining characteristic of the adult.
Because of this physical trait, their peripheral vision is actually quite poor, despite how large the eyes appear. They rely heavily on their sense of smell to find food in the substrate, which influences how we must manage their feeding and tank layout.
Pro Tip: When selecting a telescope eye at the local fish store, look for symmetry. While slight variations occur, healthy specimens should have eyes of similar size and a sturdy, well-formed Caudal fin that doesn’t droop excessively.
Beyond their eyes, they possess the classic “egg-shaped” body common to fancy goldfish. This compact body plan means their internal organs are somewhat crowded, making them more susceptible to certain health issues than their slim-bodied cousins.
telescope eye goldfish guide: Setting Up the Perfect Habitat
Setting up a tank for a telescope eye isn’t just about aesthetics; it is about safety and biological stability. These fish can grow up to 6 or 8 inches in length and produce a significant amount of waste, so “bigger is always better” when it comes to water volume.
I always recommend starting with at least a 20-gallon tank for a single fish, adding 10 gallons for every additional goldfish. This volume helps dilute the ammonia and nitrites that goldfish produce in abundance.
| Parameter | Ideal Range |
|---|---|
| Temperature | 65°F to 75°F (18°C – 24°C) |
| pH Level | 7.0 to 7.5 |
| Ammonia / Nitrite | 0 ppm |
| Nitrate | Below 20 ppm |
| Carbonate Hardness (KH) | 4 to 8 dKH |
Choosing the Right Filtration
Goldfish are “messy” eaters and have high metabolic rates, meaning they need robust filtration. However, the telescope eye is a clumsy swimmer and can easily be pushed around by strong currents.
In my experience, Sponge filtration or a high-quality canister filter with an adjustable flow rate is the best choice. A sponge filter provides excellent biological filtration where Nitrosomonas bacteria can thrive, while keeping the water movement gentle enough for the fish to rest.
Safe Decor and Substrate
The protruding eyes of these fish are very delicate and can be easily punctured or scratched. Avoid any plastic plants with sharp edges, jagged rocks, or “shipwreck” ornaments with small holes where the fish might get stuck.
Stick to smooth river stones, silk plants, or live plants like Anubias and Java Fern. For substrate, I prefer fine sand or large, smooth pebbles that the fish cannot accidentally swallow while foraging.
Maintaining Water Quality and the Nitrogen Cycle
Before adding your fish, you must ensure the aquarium is fully cycled. This process establishes the beneficial bacteria necessary to convert toxic ammonia into less harmful nitrates.
During the cycling process, Nitrosomonas bacteria convert ammonia to nitrite, and then another group of bacteria converts that nitrite into nitrate. Without this cycle, your telescope eye will suffer from ammonia burn or respiratory distress very quickly.
Weekly water changes of 25% to 50% are essential to keep nitrates low. Because goldfish consume a lot of Dissolved oxygen, I also recommend adding an air stone to ensure the water remains well-oxygenated, especially in warmer months.
Feeding and Preventing Swim Bladder Issues
Diet plays a massive role in the health of any fancy goldfish. Because of their compressed body shape, they are prone to Swim bladder disorder, which causes them to float upside down or struggle to stay submerged.
To prevent this, I always suggest using high-quality sinking pellets rather than floating flakes. Floating food often causes the fish to gulp air at the surface, which can lead to buoyancy problems.
Pro Tip: Supplement their diet with blanched vegetables like peas (deshelled), spinach, or zucchini. The fiber in these greens helps keep their digestive tract moving and prevents the impaction that often leads to swim bladder issues.
Feeding twice a day in small amounts is better than one large feeding. Only provide what they can consume in about two minutes to prevent excess food from rotting and spiking the ammonia levels.
Common Health Challenges and Disease Management
Even with the best care, goldfish can occasionally fall ill. Telescope eyes are particularly susceptible to certain ailments due to their physical structure and the “fancy” breeding process.
One common issue is Ichthyophthirius multifiliis, commonly known as Ich or white spot disease. This parasite appears as small white grains of salt on the body and fins; it is usually triggered by stress or sudden temperature fluctuations.
Bacterial and Fungal Infections
Keep an eye on the clarity of their eyes and the condition of their fins. If you notice cloudy eyes or “ragged” edges on the fins, it may indicate a bacterial infection.
Maintaining high water quality is the best preventative measure. If an infection occurs, moving the fish to a “hospital tank” for treatment with aquarium salt or specific medications is often necessary to prevent the spread to other inhabitants.
The Danger of Eye Injuries
If a telescope eye bumps into a sharp object, its eye can become dislodged or severely infected. This is why the “decor safety check” is the most important part of this telescope eye goldfish guide.
If an eye is injured, keep the water exceptionally clean. Often, with pristine water and a little aquarium salt, the fish can heal, though in some cases, the eye may be lost. Fortunately, they can live a full life with only one eye, provided the wound heals without further infection.
Choosing Compatible Tank Mates
When selecting companions for your telescope eye, you must choose other resilient species that share similar temperature requirements and swimming speeds. You should never house them with fast-swimming “common” goldfish or comets, as the faster fish will eat all the food before the telescope eye can find it.
Good tank mates include:
- Other fancy goldfish like Orandas, Black Moors, or Fantails.
- Certain community fish that tolerate cooler water, like White Cloud Mountain Minnows.
- For algae control, consider Nerite snails or larger Mystery snails.
Avoid housing them with aggressive fish or “nippers” like Tiger Barbs, which may find the telescope’s long fins and protruding eyes an irresistible target.
Frequently Asked Questions
How long do telescope eye goldfish live?
With proper care, a telescope eye can live between 10 and 15 years. Some exceptionally well-cared-for specimens have been known to reach 20 years.
Can telescope eye goldfish see well?
No, their vision is actually quite poor compared to other goldfish. They rely more on their lateral line system and sense of smell to navigate and find food.
Why is my telescope eye goldfish turning black or changing color?
Goldfish genetics are complex. Many telescope eyes start as bronze or black and may “color up” to orange, red, or calico as they mature. This is perfectly normal and usually related to genetics and lighting.
Do they need a heater?
Generally, no. They are temperate fish that prefer cooler water. However, a heater set to a stable 70°F can be helpful in rooms that experience extreme temperature drops at night.
Conclusion
The telescope eye is a rewarding and charismatic addition to the home aquarium. While they require a bit more foresight regarding tank safety and filtration than a standard goldfish, their unique appearance and gentle personality make the effort well worth it.
By following this telescope eye goldfish guide, you are setting yourself up for success. Remember to prioritize water quality, choose sinking foods to protect their swim bladder, and always keep their delicate eyes in mind when decorating.
With a little patience and the right environment, your Demekin will become a centerpiece of your aquatic world for many years to come. Happy fish keeping!