EP0514015A1 — Control of sex differentiation in fish

USPTO Abstract

Fish or shellfish eggs, fertilized embryos or hatched fry or shellfish are treated with steroid biosynthesis inhibitors or antagonists which prevents the conversion of androgens to estrogens. By blocking the production of estrogens the genotypic female is converted into a phenotypic male. The phenotypic conversion of females to males gives the treated fish the advantage of male growth characteristics. Such treatment will also allow the production of monosex populations of fish which can be used to limit reproduction and control overpopulation of specific aquatic environments. Steroid biosynthesis inhibitors and/or antagonists will also induce smoltification in salmon species.