Pearlscale Goldfish Care Guide
Pearlscale is a round-bodied fancy variety of Carassius auratus with domed, pearl-like scales and a coldwater, sensitive constitution.
Compiled by Aquairi from published sources · Published · Updated
Overview
The Pearlscale is a fancy variety of the goldfish (Carassius auratus), a cyprinid native to China and first selectively bred for colour in imperial China more than a thousand years ago. It is recognised by its spherical, egg-shaped body and its thick, domed scales that resemble pearls, giving the breed its name (the Japanese name is Chinshurin). The variety originates from China and Japan.
Taxonomy
- Family: Cyprinidae
- Genus: Carassius
- Scientific name: Carassius auratus var. Pearlscale
- Note: a selectively bred ornamental variety of Carassius auratus, not a separate species
Tank requirements
- Minimum tank volume: 150 L
- Temperature: 10-22 °C (50-72 °F)
- pH: 6.5-8.0
- GH: 5-18 °dGH
- Water flow: low
- Lifespan: 8-12 years
As a coldwater fish, the goldfish can be kept in unheated aquaria; Wikipedia notes an optimal range of about 20-22 °C and warns against exposure below roughly 10 °C or above 30 °C. The Pearlscale is reported to be very sensitive to cold water and should not be exposed to temperatures below about 13 °C (55 °F), and it is also vulnerable to rapid pH changes.
Diet
The goldfish is an omnivorous, opportunistic feeder. In the wild its diet consists of crustaceans, insects and various plant matter. Because of the Pearlscale's compact, rounded body, overfeeding should be avoided.
Compatibility
The variety is peaceful and slow-swimming. Owing to its rounded shape and reduced mobility it is best kept with other fancy goldfish of similar build rather than fast, active tankmates that may outcompete it for food.
Health notes
Selective breeding for an extremely rounded body makes the Pearlscale susceptible to swim-bladder disorders, which affect its ability to maintain a normal position in the water. Extreme conformations can also cause problems with the spine and internal organs, reducing quality of life and longevity. Stable, clean water is therefore important.
Pearlscale Goldfish Breeding Guide
Overview
The Pearlscale is a domesticated variety of Carassius auratus, spherical-bodied with finnage similar to the fantail and veiltail, and scales protruded into white domes that resemble pearls. Like all goldfish it is an egg-scatterer, and the domed scales are a direct result of selective breeding over generations. Some extreme fancy goldfish are much less hardy than forms closer to the wild original.
Conditioning
Goldfish reach sexual maturity only with sufficient water volume and the right nutrition. Mature, healthy adults are conditioned before the breeding season. The optimum temperature for goldfish is between 20 and 22 °C (68 and 72 °F); temperatures under about 10 °C (50 °F) are dangerous to fancy varieties and temperatures over 30 °C (86 °F) can also cause harm.
Breeding Setup
Provide dense aquatic vegetation such as Cabomba or Elodea, or a spawning mop, because the eggs are adhesive and attach to this material. A separate spawning tank lets the adhesive eggs be protected, as adults may eat young they encounter.
Spawning Behavior & Trigger
Breeding usually happens after a significant temperature change, often in spring. Males chase gravid females and prompt them to release their eggs by bumping and nudging them. The female scatters adhesive eggs across the plants or spawning mop.
Egg & Fry Care
The eggs hatch within 48 to 72 hours. In their first weeks of life the fry grow quickly, an adaptation born of the high risk of being eaten by adult goldfish, other fish and insects. Within a week or so the fry begin to assume their final shape, although a year may pass before they develop mature goldfish color; until then they are a metallic brown like their wild ancestors.
Common Challenges
The raised, dome-like pearl scales are a fragile selectively-bred trait: damaged domes do not regenerate in their original pearled form. Some highly selectively bred goldfish can no longer breed naturally due to their altered shape, and heavy culling of fry is needed to keep only those that develop the spherical body and well-formed domed scales.