17α-methyltestosterone (MET) is an aquaculture premix and is only available through Rangen Inc. The primary goal of studies conducted under INAD #11-236 is to generate data evaluating the efficacy of MET administered in feed to larval tilapia to produce populations comprised of >90% male fish. The treatment option that is allowed is a dose of 9 mg active drug/kg of fish biomass.  MET will be incorporated into tilapia feed by Rangen, Inc. at a rate of 60 mg MET/kg feed.  Therefore, based on standardized procedures for tilapia production, newly hatched tilapia fry should be fed 150 g MET-medicated feed/kg fish biomass/day (i.e., fed at 15% body weight daily).  MET-medicated feed should be fed to tilapia fry for 28 consecutive days.  No retreatment will be allowed. Investigational Withdrawal requirements (days or individual fish weight) depend on whether fish are reared in a "batch culture system" (120 d Investigational withdrawal period) or a "partial-harvest/restock culture" system (individual fish must weigh at least 350 g before being taken to market.)  Note: if formalin or diquat is used during the MET treatment, then the withdrawal time for the drug with the longest withdrawal period must be followed. This INAD requires all participant facilities to be approved by the FDA Environmental Team prior to participation – this review will take 100 days. To participate in the INAD Program for MET visit the data collecting site.

Please read the Study Protocol prior to any treatments. It contains the protocol 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) and the SDS for this INAD are currently only available by emailing Bonnie Johnson .

Rangen Inc. P.O. Box 706 Buhl , ID 83316 United States

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