Pearlscale goldfish break the rules for fancy goldfish breeds: They are one of the most visually striking fancy breeds, yet they grow to be very large and are just as suited to a pond as to an aquarium. They need more room than your average fish, and a special diet.
A Fish of Remarkable Size
Pearlscale goldfish grow to an average of 5 to 7 inches long, but some can grow to be 10 inches or longer. Like other breeds, if they are kept well they can live a decade or more, and the older they are the bigger they'll get. Length from their back to their belly will measure about 2/3 of their length from nose to tail tip, and their width is also impressive. Young pearlscale goldfish are shaped roughly like a golf ball. Adult ones are described as the size and shape of a large orange.
Pearlscale goldfish are so named for their nacreous (pearl-like) scales. These bead-shaped scales are different from the flat scales of all other goldfish breeds. Oddly enough, if a pearlscale loses a beady scale, it will grow a flat scale in its place. Their bodies are very short and round, and the fins and tails of most pearlscale varieties are short in proportion to their bodies.
Because of its three-dimensional expansion in size this breed needs even more room than other goldfish breeds. A 30-gallon tank is considered the minimum to keep one pearlscale healthy and happy, with at least 10 more gallons needed for each additional fish. Unlike other fancy goldfish breeds, they do excellent in outdoor ponds. Like other fancy breeds, their speed and agility are limited by their body shape. So all decorations and hiding places should be smooth and rounded to prevent injuries, and they should never be kept with fast, aggressive fish.
A Diet for your Fat Fish
Pearlscale goldfish need a special diet to keep up their special physique. Their calcium requirements are high because of the structure of their nacreous scales, and their guts are very compact and delicate. Dry food such as flakes and pellets can make your pearlscale very sick. Pearlscales do well on fresh and frozen meat and vegetable foods. Good meaty foods are bloodworm, daphnia, brine shrimp ("sea monkeys") and carnivore-blend frozen cube foods. Good vegetable foods are frozen spirulina cubes and herbivore blends; fresh romaine lettuce, kale (not all fish will eat this), and cucumber; thawed frozen peas; and inexpensive, prolific aquarium plants such as anacharis.