Near the end of World War II, when food supplies were running low for the Japanese Imperial Army, it bred a special “imperial fish” as a food source in colonised Singapore. A species of tilapia imported from Java, Indonesia, the fish was cultivated in Singapore by a team of Japanese and Taiwanese breeders who served the Imperial Army. But heavy storms caused the fish farms to flood, and these fish escaped into local canals and interbred with other species of tilapia — and these hybrid fish are the most common fish in Singapore’s waterways now.
After the Japanese surrendered, Guo Qizhang and Wu Zhenhui, two Taiwanese Imperial Japan servicemen, broke into the Singapore fish farm and stole some fish fry. Only 12 fish made it back to Taiwan in 1946. They began a successful breeding programme which grew into a lucrative post-war industry of fast-growing, cheap white meat. Now the tilapia is the most farmed fish in Taiwan, named “wu guo fish”, after the surnames of the two Taiwanese soldiers.