Koi fish is one of the most important culture symbols in Chinese and Japanese culture. Koi fish are capable of adapting to many different climates and water conditions and can symbolize strength. It is inherent in a koi's nature to swim upstream therefore they symbolize great determination, dedication, perseverance to achieve success.
Often paired with the yin-yang symbol, the sides are said to resemble a female and a male koi swimming together, representing the harmony of two opposite energies coming together as one, creating a perfect balance. In Taoism, yin and yang further symbolize the dueling sides of all things and the perfect balance and harmony of them. The circular movement of the fish represents the belief that all things in life are connected.