鯉

Koi (鯉) simply means 'carp' in Japanese. The decorative varieties — nishikigoi (錦鯉, 'brocaded carp') — were developed in 19th-century Japan from Chinese carp.

Carp were originally raised for food. Japanese farmers noticed color mutations and began breeding for beauty rather than meat. The hobby became an art.

Koi symbolize perseverance in Japanese culture — the legend says a koi that swims up a waterfall transforms into a dragon. Koi tattoos carry this meaning.

Now 'koi' in English means specifically the ornamental fish. Japanese gardens and suburban ponds alike feature koi, though quality varies enormously.