Koi are beautifully hued and expensive carp formally called nishikigoi in Japan. The fish, appreciated as "swimming jewels," represent good luck in life and business.

A koi fish seller says business is booming, thanks to his careful attention to detail. He sometimes visits 20 breeders a day to source fish that can sell for thousands. By Zahra Tayeb ...

The president was in Japan visiting with Prime Minister Shinzo Abe on Monday, Nov. 6 when the pair visited the Akasaka Palace koi pond.

In recent years, koi have become hugely popular in Asia, with Japan’s koi exports doubling over the past decade to 6.3 billion yen ($43 million) — one-fifth of them shipped to China, the top ...