The Comet is a commonly kept form of goldfish, the only type to have originated in the United States. They first appeared in the ponds of the Fish Commission in Washington in the early 1880s. Hugo Mullertt was the first person to bring the Comet goldfish to the market in a large quantity.
Characterized by a long, tall, flowing tailfin they can be differentiated from the common goldfish, although otherwise they are very similar. Both of these varieties are quite hardy and will do well in an outdoor pond, as well as in indoor cool-water aquariums; however, they should not be kept in “goldfish bowls”, as they grow much too large and require frequent water changes and/or filtration. There are also several different varieties of Comet including the Sarasa comet which has a red and white pattern. Another is the Calico comet which appears to be very much similar or the same as the shubunkin, a calico-only single-tailed breed. Comets have a lifespan of approximately 7 to 14 years and thrive in temperatures close to freezing. They can grow to reach 12 inches in length.