patrick.net

A team of researchers in Japan has succeeded in making catfish all female with a compound found in soybeans -- a development that promises to increase the production efficiency of this and other species whose females are more valuable than males in the food market.

The team, from Kindai University's Aquaculture Research Institute and based at the institute's Shingu Station in Shingu, Wakayama Prefecture, used isoflavone -- a compound found in soybeans similar in effect to female hormones -- to create the all-female groups of catfish. The feat is a Japan first, according to the university.

As female catfish grow faster than males, "by making them all female, production efficiency will rise," commented team leader and aquaculture science associate professor Toshinao Ineno. "This can be applied to other farm-raised fish whose females are more valuable." ...

While 68% of catfish in the ordinary water tank were female, 96% of the catfish kept in the water with genistein at a concentration of 100 micrograms per liter were female. A concentration of 400 micrograms per liter yielded a 100% female group, the same as in the female hormone-treated water group.

A team of researchers in Japan has succeeded in making catfish all female

That happens naturally with ocean fish around here. Part of nature that fish turn from male to female as they age.