Black Comet

The Black Comet is technically a Koi/Comet hybrid.  They are a peaceful and hardy fish that require colder water, great for eating unwanted duckweed and grow to almost 30 cm.  They are easy to care for and great for beginners.

The Comet Goldfish, also known as Carassius auratus auratus, has been with us since the end of the 1800s. Hugo Mulertt is credited with the selective breeding program which led to the creation of this fish from wild Prussian Carps. The Comet Goldfish got its name because of its long flowing golden tail which resembles a comet.

Behaviour

Comets are one of the more active breeds of Goldfish and are very fun to watch. They are fast swimmers and will spend lots of time exploring their surroundings.  Also, contrary to popular belief, they can remember their owners and their tank surroundings and decorations. For this reason you can switch up the decorations in your aquarium every couple of months to keep it interesting for them.  They can become aggressive during feeding, so to help ease this you can place feed at both sides of the tank to reduce competition for food.

Tank Conditions

Its recommended to use a long rectangular shaped aquarium to provide plenty of space to swim in.

For substrate just about any size will work.  For smaller fisher finer sized gravel is recommended.  In terms of decoration and plants, plants are crucial to oxygenate the water. In addition they provide hiding places to help them feel safe and also act as food for your Comets, as they’ll occasionally nibble the plants. Anacharis, Hornwort and Java Fern all make ideal candidates.  Comets love to eat floating duckweed and it gives them the needed plant fiber in their diet.

All goldfish require cold water. This means that you should keep your tank away from any heat sources and keep it in a cool room. If you place them in water that is too warm for them it can cause lifelong damage to their nerves.  Ideally the water temperature should be between 10 – 24°C.   pH level between 6.5 and 7.5.

As for filtration you can’t really over-filter a tank with goldfish in; they produce a surprisingly amount of bio-load which can impact the condition of the water. You can use a hang-on-back filter or if you have the budget a canister filter would be better.

First, you should know that the myth of goldfish only growing to the size of the tank is wrong and incredibly damaging to your fish. As a minimum you should aim for at least 150 litres per Comet Goldfish.

Compatibility

Unfortunately they don’t make good tank mates, this isn’t because they are aggressive, and it’s due to these two main reasons:

• Although Comets live in freshwater, they are not tropical. This means you won’t be able to keep them with other popular freshwater fish, as the warm water is too hot for them.
• Second, they tend to consume lots of food, so other fish in the tank are at risk of being malnourished.

For this reason the bulk of options for other tank mates come in the form of other goldfish and koi. We would recommend keeping it simple and keeping them with similar sized varieties such as the Common, Shubunkin, Wakin and Jikin goldfish.  If you are looking to include other tankmates you can look at:

• Zebra Danios (they prefer lower temperatures)
• Bristlenose Plecos
• Weather Loaches
• Rosy Barbs

Remember though with any non-goldfish you will be playing a balancing act with the temperature of the tank.

Feeding

In their natural environment Comets will feed on plants, small insects, algae and anything else they can get hold of; however the majority of their diet is vegetation (this provides them with plenty of fiber). Generally you can start by feeding your Comets goldfish pellets or flakes.  If you want your fish to have bright coloration, a varied nutritious diet is crucial and one can try fancy goldfish foods.  For meat sources you can feed them tubifex worms, bloodworms or for larger fish mealworms.

Care

One common illness with comets (bloat) is caused by overfeeding so best to err on the side of caution.  It will take comets around 3-4 years to reach their full size. Like other Goldfish, the Comet is prone to some common health problems including:

• Goldfish Ich
• Fin Rot
• Fungal Infections
• Swim Bladder Disease

Click for Fish Disease Diagnosis and Treatment at Rebel Pets.