Creating All-Female Catfish Without The Use Of Hormones

So claims a team of researchers from Kindai University’s Aquaculture Research Institute, in Japan. Rather than hormone treatment they used isoflavone – a compound found in soybeans – to create the all-female groups of catfish, in the first project of its kind in Japan.

According to the project’s team leader, Professor Toshinao Ineno, females reach market size, of 600 g, 6-10 months after hatching. Males, which grow more slowly, are often discarded by fish farmers.

“By making them all-female, production efficiency will rise,” the project’s team leader Prof Ineno, is quoted as saying in The Mainichi. “This can be applied to other farm-raised fish whose females are more valuable.”

While researchers have long known that administering female hormone turns male catfish into females, this isn’t permitted for fish destined for human consumption. However, Prof Ineno considered using soybean isoflavone, which is sold commercially as a dietary supplement.