17 β -estradiol (E2) will be administered as a medicated feed and is only available to FDA approved facilities. The primary goal of studies conducted under INAD #12-671 is to generate data evaluating the efficacy of E2 administered in feed to larval brook trout to produce feminized male fish that produce eggs. The treatment option that is allowed for brook trout is a dose of 20 mg active drug/kg feed at 4% body weight per day to fry for 60 days. No retreatment will be allowed. No release of treated fish with E2 will be allowed. This INAD requires all participants to be approved by the FDA Environmental Team prior to participation – this review will take 100 days. To participate in the INAD Program for E2 visit the data collecting site.

Please read the Study Protocol prior to any treatments. It contains the protocol, SDS, and a copy of the forms to be used as a guide for collecting data that will be entered into the online INAD database. The FDA authorization letter(s) for this INAD is currently only available by emailing Bonnie Johnson .

Sigma-Aldrich, Inc 3306, 3300 S 2nd Street St. Louis , MO 63118 United States

Brook Trout: 20 mg 17 β E2/kg feed at 4% body weight per day

No release of treated fish with E2

Investigator needs to report general fish behavior and any adverse effects relating to treatment.

Working with others to conserve, protect and enhance fish, wildlife, plants and their habitats for the continuing benefit of the American people.