Lots of people aren't aware that there are many different kinds and variations of the goldfish available to purchase. Here is a list of some of the different types of goldfish.
Bubble Eye Goldfish: The bubble eye is very similar to celestial goldfish. It too has a torpedo like body with no dorsal fin, but it differs in that it has big fluid filled sacs under and around the eye. These sacs are very delicate and can be easily punctured by other fish and tank decorations so they do not make a good choice of goldfish for the beginner. Their poor vision also makes them more difficult to keep and they should only be kept with slow moving fish.
Telescope Eye Goldfish: These quaint individuals have protruding eyes that give them a quirky expression. They are also known as the dragon eye, globe eye and demekin goldfish. They can have both metallic and nacreaous scales and they come in a wide range of colors from black and red to calico. They have poor eyesight and should be kept in an aquarium free of sharp objects with other slow moving goldfish. Not a goldfish for the beginner.
Lionhead Goldfish: The lionhead goldfish along with the similar ranchu goldfish originated in China and were introduced to Japan during the 17th century. They lack a dorsal fin and have large heads due to the "wen" or headgrowth covering its gills, cheek and head. These goldfish are slow swimmers and should only be kept with slow moving fish.
Black Moor Goldfish: The black moor goldfish is highly popular because of its black velvety appearance. It is similar to the telescope goldfish in that its eyes protrude, making it an unsuitable candidate for aquariums with competitive or fast moving fish. This goldfish prefers water temperatures above 60 degrees Fahrenheit and pH values between 6.5 and 7.5.
Pearlscale Goldfish: This goldfish has thick, domed scales which give it a pearl like look hence its name. The pearlscale goldfish has an egg shaped body very similar to the fantail goldfish. The pearlscale is sensitive to temperature fluctuations and shouldn't be kept in water with high alkaline levels.
Jikin Goldfish: The jikin goldfish is one of the most beautiful types of goldfish around. They have a unique x-shaped tail when viewed from behind. This goldfish is also known as the butterfly-tail goldfish. They are quite hardy and rare goldfish that do well both in an aquarium and outdoor ponds.