In Chinese culture the koi, or carp, stands for perseverance and success. Legend says a carp that swims up the Yellow River and leaps the waterfall called the Dragon Gate turns into a dragon. Fish also stand for abundance, because the Chinese word for fish sounds like the word for surplus.
The carp that leaps the Dragon Gate
In the old story, many carp try to swim against the current to the top of the falls. Most give up. The one that makes the leap is transformed into a dragon. In imperial China, passing the civil service examinations was called "the carp leaping the Dragon Gate," and the phrase is still used for exams, promotions and any hard-won breakthrough.
Fish and abundance
The Chinese word for fish, yu, sounds like the word for surplus. A common New Year greeting, nian nian you yu, wishes "abundance year after year," and fish appear on New Year decorations and on the table for the same reason. A pair of fish adds a wish for a harmonious marriage.
The golden fish in Buddhism
A pair of golden fish is one of the Eight Auspicious Symbols of Tibetan Buddhism. Fish swim through water without fear of drowning, and the pair stands for moving through the ocean of suffering without fear.
Koi with other symbols
Koi often appear with a peace buckle, wishing safety alongside success, or on a red string for luck. Some rings carry the Heart Sutra beside the fish.