STEPHEN D. MCCORMICK,1 SHUNSUKE MORIYAMA,2 AND B. THRANDUR BJÖRNSSON3 1Conte Anadromous Fish Research Center, Biological Resources Division, US Geological Survey, Turners Falls, Massachusetts 01376; 2Laboratory of Molecular Endocrinology, School of Fisheries, Kitasato University, Sanriku, Iwate, Japan; and 3Fish Endocrinology Laboratory, Department of Zoology, Göteborg University, Göteborg, Sweden