Aquaculture for all

Researcher Creates Supermale Bluegill

Breeding & genetics

OHIO, US - All of the fingerling bluegill swimming in the grey tank with a scarlet 36 on it look about the same.

But a quarter of them are "super males", wrote Doug Caruso of the ColumbusDispatch.

They're the key to growing ponds full of all-male bluegill. Since male bluegill grow twice as large as females, fish farmers can provide larger fillets for people's dinner plates. That would mean larger profits.

Han-Ping Wang, principal research scientist at Ohio State University's aquaculture lab in Piketon, is close to achieving that goal using a process that starts, oddly enough, with turning all the fish into females.

He introduced estrogen to tanks of bluegill that had a natural population of about half male and half female. In the right amounts, the hormone turns all the fish into egg-producing females.