Sales of Farmed, Feminized Eels Spreading in Japan

Tokyo, Nov. 27 (Jiji Press)–Sales of cultivated feminized eels are beginning to spread in Japan, as the Aichi Fisheries Research Institute in central Japan and others have successfully developed a method to feminize eels. While over 90 pct of glass eels under cultivation become male, the method can nurture nearly all of them to become female by providing special feed. Female eels grow to twice the weight of males. “An era in which consumers can choose to eat male or female eels is just around the corner,” Hiroyuki Inaba of the Aichi institute said at an event in Nagoya, the capital of Aichi Prefecture, on Nov. 18. Inaba and others established the eel-feminizing method, which provides glass eels with feed containing soy isoflavone, which has a structure similar to female hormones, for a certain period. They obtained a patent for the method in 2021. Although the method requires longer cultivation periods, female eels grow to weigh 400-500 grams each. Data show that their meat contains more “umami” and has softer textures. In July, Aeon Retail Co. offered farmed, feminized eels as “kabayaki” grilled products for the first time. For the Day of the Ox, the major supermarket operator prepared some 60,000 eels, and they sold well, according to company officials. “It was a sustainable initiative in terms of using limited resources effectively,” said an Aeon Retail official. Convenience store chain operator Lawson Inc. also launched bento products using farmed, feminized eels for the first time this year. Both Aeon Retail and Lawson are considering selling such products again next year. According to a local fishery cooperative in the Aichi city of Nishio, the proportion of female eels to overall eel shipments is around 30 pct by weight. Eel farming areas in other prefectures, including Shizuoka and Kagoshima, have introduced similar feminizing methods. Such moves are “expected to spread further,” said an Aichi prefectural official. This month, a meeting of signatories to the Convention on International Trade in Endangered Species of Wild Fauna and Flora was held in Uzbekistan to discuss restricting transactions of all eel species. Tighter restrictions would certainly trigger a surge in eel prices. In that case, demand for female eels, which are larger than males, could rise. END [Copyright The Jiji Press, Ltd.]