A clear guide to the key terms used in goldfish keeping and buying
Considered the pinnacle of goldfish breeds, the Ranchu has a rounded body with no dorsal fin and a prominent head growth (wen). A star of goldfish shows, it is highly prized among hobbyists and requires some experience to keep.
A quintessential goldfish breed with a rounded body and long, flowing tail fins. Available in red, white, calico, and more, the Ryukin is hardy and easy to care for, making it ideal for beginners and a joy to watch.
A distinctive goldfish breed with protruding eyes on both sides of the head. It comes in red, black, and calico varieties. Due to its somewhat poor eyesight, a tank layout free of sharp objects is recommended.
The most ancestral goldfish breed, with a streamlined body similar to a crucian carp. Robust and strong swimmers, Wakin are the easiest goldfish to keep and a staple of Japanese goldfish scooping games. They can live over 10 years.
A condition in which a goldfish floats at the surface and cannot swim normally, caused by swim bladder dysfunction or indigestion. It is most common in round-bodied breeds and can be prevented by avoiding overfeeding and sudden water temperature changes.
A disease caused by the parasite Ichthyophthirius multifiliis, appearing as small white spots on the fish's body. It is often triggered by sudden temperature changes or stress. In early stages, raising the water temperature to 28–30°C or using salt baths can be effective treatments.
A treatment and prevention method involving keeping goldfish in a 0.3–0.5% salt solution. It reduces osmotic stress on the fish's body and boosts its natural healing ability. Widely used as a first response to illness and during recovery.
A unique goldfish breed with large fluid-filled sacs beneath the eyes. Originating from China, it is prized as an ornamental fish. The delicate bubbles are easily ruptured, so tanks should be free of sharp decorations.
Aquarium water that has turned green due to the growth of phytoplankton, also known as green water. In Ranchu keeping, it is believed to enhance body coloration and promote head growth (wen) development.
A traditional Japanese festival game where players scoop goldfish using a thin paper scooper called a poi. To keep the goldfish healthy after taking them home, it is important to set up a proper tank and acclimate them to the new water.
A state in which goldfish reduce activity and slow their metabolism to survive winter when the water temperature drops below 10°C. Outdoor goldfish enter dormancy naturally. During this period, feeding should stop and water changes should be kept to a minimum.
Refers to the shape and spread of a goldfish's tail fin. Types include triple tail, quadruple tail, cherry blossom tail, and streamer tail. In goldfish shows, tail symmetry, firmness, and spread are key judging criteria.