Comet Goldfish (Carassius auratus)
Native Location: China
Size: 30cm (12 inches)
Temperature Range: 18 – 21℃ (60 – 75℉)
Preferred pH Range: 6 - 8
Minimum Aquarium Size: 200 L (50 gallons)
Potential Tankmates: Shubukin
Care Level: Intermediate
Bred captively from wild Prussian Carps back in the 1800s, Comet Goldfish have been widely popular ever since. Their hardiness, vibrant colours and potentially long life make them perfect for aquarium hobbyists.
Comets will eat mostly plant material but also animal matter. They will try to eat anything they can get their little fins on. Comets are descendants of wild Prussian Carp, who feed on plants, small insects, and algae, so a Comets diet is the same. Start by feeding them goldfish pellets of flakes. For varied nutrition, try treating them with bloodworm. Comets do not make the best tankmate, because they are freshwater fish, NOT a tropical species. Meaning they cannot be kept with popular aquarium fish as Comets will not stand the warmer temperatures. Comets also require, or at least hoard, much more food to themselves, potentially harming your other fish who could become malnourished. Keep Comets with different breeds of Goldfish or Koi. While they are usually a peaceful species, Comets can become aggressive during feeding time. To minimise this behaviour with multiple fish, try placing feed at either end of your aquarium to reduce the competition.
Live vegetation may become a target for their stomachs. But do not let this discourage you. Plants like Java Fern provide cover and will make your Comets feel safe. Use small gravel for the substrate. There is another challenge with housing more than one Goldfish. You will need enough space for them. 189L (50 gallons) per fish to be exact! That is why they are so popular in outdoor ponds where they can be kept in large numbers.
A Comet gets its name from its long flowing, golden tail that mimics the night sky marvel we can see from time to time. Other breeds of Goldfish do not have this feature, usually having stiffer fins. Healthy Comets should not have bulging eyes and flat scales. The pectoral or side fins are a way to tell the gender difference. The first ray of the pectoral fin on a mature male is thicker than on a mature female. Females, when viewed from above, have wider bodies than males. Their plumper bodies are also more noticeable around breeding periods. It is considered almost impossible to breed Comets in aquariums because there will not be enough space. Ponds are the best option. Coldwater is the way to trigger their mating season. If successful, males will start chasing around females, then a female may decide to release her eggs into nearby plants. If you do not use a spawning mop to remove the fertilised eggs from the pond, their parents will likely eat them.