Koi
The major named varieties include:Goldfish (金魚) were developed in China more than a thousand years ago by selectively breeding Prussian carp for color mutations. By the Song dynasty (960–1279), yellow, orange, white, and red-and-white colorations had been developed. Goldfish ("Carassius auratus") and Prussian carp ("Carassius gibelio") are now considered different species. Goldfish were introduced to Japan in the 16th century and to Europe in the 17th century. Koi, though, were developed from common carp in Japan in the 1820s. Koi are domesticated common carp ("Cyprinus carpio") that are selected or culled for color; they are not a different species, but a subspecies, and will revert to the original coloration within a few generations if allowed to breed freely.
Lionchu
Although at first, the lionchus were considered merely as mongrels, being hybrids of the lionheads and ranchus, the lionhead actually have an ancestor from Japan in the 1800s; it is then known as
the shishigashira ranchu or lion-headed ranchu. The shishigashira ranchu is a ranchu-like goldfish with small amounts of headgrowth and some having small knobs and bumps on the back (a suggestion that the absence of the dorsal fin had not yet been stabilized at the time). But the modern-day lionchu is considered to have originated from Thailand, and was popularized by a group of goldfish hobbyists in Singapore through RafflesGold.com, an internet-based goldfish forum site. The lionchu was officially recognized as a unique class of fancy goldfish during the "My Fancy Goldfish Competition 2006", which was held in Singapore from May 26–28, 2006.