Comet Goldfish: The Complete Care And Breeding Guide

Due to its bright colors and trademark forked tail, the Comet goldfish is one of the most popular aquarium fish worldwide. 

This particular species is perfect for beginner fish keepers because of their tolerance to different water qualities and typically low levels of maintenance.

Origins Of The Comet Goldfish

The Carassius auratus auratus, better known as the Comet Goldfish, has existed since the 1800s. This particular fish was created from a process of selective breeding from Prussian carps, first credited by Hugo Mulertt. 

They originated from the Crucian carp, and similarly to the Koi fish, they were kept primarily as a food source. As a result of selective breeding and generational changes, they began to mutate in color, and so fish keepers began keeping the different colored variations of this fish. 

Selective breeding and crossbreeding have led to a plethora of different Goldfish existing that all have different features, like the orange and Ranchu variations, for example.

Comet Goldfish Colors And Features 

Common Goldfish have quite short, stiff fins, whereas the Comet goldfish gets its name from its flaring golden tail, which resembles a comet. They are also usually a little smaller in size compared to a normal goldfish; the comet goldfish will have a slim body with a longer tail and anal fin.

Goldfish are typically anywhere from brown, orange, gold, white, and tan colored. Their bodies are usually one solid color, although they may have patches or stripes of another color as well. 

Traditionally, the comet goldfish is a bright orange color, originating from a fish that was originally a light tan color with a gold belly; hence their name ‘Goldfish.’ With the offspring of any goldfish, however, their colors can vary greatly. 

Comet goldfish, in particular, will also change their color according to a variety of factors, including age, diet, or even water quality. 

Sarasa Comets, for example, which appear slightly more elongated, will usually have white bodies with deep red colors. As well as red, white, and orange, you can also find Comet/Koi hybrids which are black in color.

When kept nutritious and healthy, Comet Goldfish can live for 14 to 20 years and grow up to 12 inches in length; therefore, a large tank is needed for these hefty growers.

The Differences Between Comet Goldfish Genders

When Comet Goldfish are kept in an environment with good water quality, temperature, and nutrition, their gender differences will become more evident. 

Male Comet Goldfish will often develop papules on their pectoral fins and operculum that will be more or less noticeable depending on the season. Most people mistake these papules for an unwanted health condition or tumors, but you should be aware that is more than normal, although it is more common in Goldfish that are kept outside in natural habitats like a pond, for example. 

On the other hand, the females will usually be larger and more rounded in shape and will not develop external papules. 

Typical Behaviour Of A Comet Goldfish 

Comet Goldfish are very active and love to swim around exploring their habitat, making them a fun fish to keep and spend hours watching them do their thing. 

Contrary to the popular idea of a goldfish having a poor memory, they will actually remember their owners and tank surroundings quite well. This is why it can be interesting to spruce up their habitat now and then so as to keep the fish busy and occupied; they will undoubtedly enjoy seeing some new features in their aquarium from time to time and certainly won’t forget their surroundings in three seconds.

How To Feed A Comet Goldfish

Feeding your Comet Goldfish is a straightforward process, as many pet stores sell many types of fish food designed specifically for Goldfish. 

The Comet Goldfish is an omnivore, meaning they will eat a mixture of both plant and animal matter. In their natural habitat, they will consume mostly vegetation but will also eat things like algae, plants, and small insects or other small fish. 

They will prefer a pellet-based diet, preferably with a protein content of around 30-32% for the ideal nutritional values. For Goldfish, a pelleted diet is more appropriate than flakes, as they will have better nutritional values without clogging up the bed of your tank. 

One thing to consider is that, depending on the temperature of your fish tank, your Goldfish should be fed accordingly. For instance, if the tank is 70F or above, you may feed them twice a day, although if the tank is less than 70F, you can only feed them once a day. 

Similarly, with many fish species, you can also make some additions to their diet for some extra nutrition. A varied diet will also increase the coloration and brightness of their appearance. 

You can supplement their diet with things like bloodworms, larvae, worms, small insects, and also with a variety of common greens such as peas, cucumber, lettuce, and broccoli. 

Ensure you do not overfeed your Comets, however. They have a big appetite and will pretty much eat all the time if they are given the option, so make sure to only feed them 2-3 times a day at most. If you overfeed them, you will have to ensure you collect all the remaining food that is left at the bottom of the tank as they will usually save this for later; they sometimes overeat and get ill by bloating – you’re not the only one. 

The Ideal Habitat For Your Comet Goldfish

A perk of keeping Comet Goldfish is that they can withstand a variety of water qualities, although you should still ensure a well-maintained habitat for your fish. 

Do not be fooled by the stereotypes in films that see Goldfish being stored in small fishbowls; this particular breed needs a lot of room to grow, and so it is advisable to keep a tank that can store up to 50-gallons of water. It is possible to start with a smaller tank of 20 gallons, for example, but you would need to up the size of the tank as the fish grows. 

An appropriate substrate for the Comet Goldfish would be things like gravel or sand, as they enjoy buying and messing around with the debris below them. If you’re lucky, you may even spot them moving little pieces of debris around sometimes, but just be aware in case they get stuck amongst anything and injure themselves; they are pretty robust, however. 

In fact, they can be a bit of a nuisance in that sense – they are known for eating live plants for no particular reason, as well as engage in some interior design by moving around their tank accessories. 

You can keep multiple Goldfish together, but you should remember that they need a lot of space; you should allow for up to 50 gallons for each one, so this quickly adds up to huge tanks if you keep too many.

Be aware that Goldfish are freshwater fish, and so they require a cold habitat to thrive. If you keep your Comets in a habitat that is too warm, they will be more prone to diseases and nerve damage. 

A water temperature of around 50-75F should be ideal, meaning that you can usually just keep your Goldfish in a tank that relies on natural room temperature; extra heating might not be necessary. 

The ideal pH level for Comet Goldfish is around 6.5-7.5. 

When it comes to the ideal filtration system for Goldfish, you can simply use a hang-on-back filter or a canister filter. Goldfish can generally produce a large bio-load which can decrease the quality of the water around them, so you should keep the filtration system working thoroughly. 

Ideal Tankmates For A Comet Goldfish 

Generally, Goldfish are very peaceful and so can involve themselves with a variety of tank mates when it comes to sizes and breeds; they can be tricky tankmates, however. 

One thing you must consider is that although a Comet’s natural habitat is freshwater, they are not actually tropical fish. This means that it is hard to keep them with other freshwater fish as the water temperature can be too hot for them. 

Also, because Comet Goldfish are big eaters, you will often find them consuming the majority of the food you place in the tank, meaning that other tankmates will not benefit from the greediness of your Goldfish.

For this reason, it is best to choose fish that are large enough to not be accidentally eaten by the Goldfish, but also ones that are suited to less than the tropical temperature that Goldfish prefer; this will also ensure your Goldfish do get too hungry. 

Examples of good tankmates include minnows, zebrafish, snails, and of course, other Goldfish such as the Common variety, Wakin, Jikin, and Shubunkin Goldfish. You can also implement breeds like the Zebra Danios, Weather Loaches, Rosy Barbs, and Bristlenose Places. 

Like the Koi fish, they can also be kept in a small outdoor pond if that’s your style; they can tolerate many different temperatures and will not grow that big.

How To Breed Comet Goldfish

Breeding Comet Goldfish can be quite a tricky task as they usually need more space than just your average aquarium tank; if you have a pond, this will be an ideal option for breeding.

When spawning, Comet Goldfish can be quite messy; they will often send sperm and eggs floating everywhere within their habitat. It is also important to note that if you wish to breed the fish inside, you will need to ensure their day and night light cycles are recreated to match their natural cycles. 

The best way to start breeding Comet Goldfish is to raise the temperature of their habitat. As they are originally freshwater fish, they are used to colder temperatures, and so in order to start the breeding process, you should look to keep the Goldfish in a cooler temperature of 55-60F, then slowly increase the water temperature to around 70F after a month or so. The reasoning for this is that it mimics the rise in water temperature that naturally occurs during springtime. 

A way to tell if this breeding method has been successful is to look for spawning behavior; The male should start chasing the female around the habitat, attempting to breed by touching her stomach. If the male is successful in his efforts, the female will release up to 1000 eggs into a nearby plant or patch of debris. 

Once the eggs have been laid, you should use a spawning mop to relocate the eggs to a different aquarium used only for breeding. This will prevent the Goldfish parents from eating their eggs, later on, something which is a natural process but one that is best to avoid.

The laid eggs in their newly acquired habitat should be left for a week at temperatures of around 70F. Shortly after, they will begin to hatch; within a few days, you will have a new school of small Comet Goldfish swimming around your enclosure.

What Are Common Comet Goldfish Problems To Look Out For?

The Comet Goldfish is susceptible to the usual array of health problems that Goldfish are prone to. 

You should look out for health issues like Swim Bladder Disease, Fin Rot, Goldfish Ich, and Fungal infections.

Summary

Comet Goldfish can be a great addition to any fish keeper’s collection; they are bright and exciting in both their appearance and their personality. 

Things that you must remember, however, are that although they are suitable for beginners due to their robustness, you will need a large tank in order to keep them, making them quite high maintenance compared to other options of beginner fish. 

Remember to feed them twice a day, but not overfeed them; they are greedy fish and will eat whatever you offer them. 

You can also gain some peace in knowing that they won’t forget you or their surroundings in three seconds, so enjoy their presence and take good care of them.