Small impoundments stocked with bluegill often become overcrowded with small, undesirable fish. This problem would be prevented if it were possible to stock only one sex, but sexing of small bluegill is difficult and unreliable. Monosex broods in Oryzias latipes , Tilapia mossambica , and Carassius auratus  can be produced by using sperm from sex-reversed genotypic females to fertilize eggs from normal females. The objective of this research was to develop a method for changing sex in bluegill fry by administering androgens.
Additional publication details
The effects of methyltestosterone on sex reversal in bluegill