The comet goldfish can be distinguished from the common goldfish by its long, single and deeply forked tail fin. Comets with yellow, orange, red, red-and-white color are common. Due to the comet`s hardy and active nature, and the relative ease in caring for them, they are best suited to ponds and outdoor pools. Comet-tails can grow up to 12 inches in length.Sarasa Comets have long flowing fins and are very hardy fish. They can be kept with koi in an outdoor pond.These comet goldfish have a natural life of approximately 7 to 14 years and there are chances to live much longer in excellent conditions.