I must've gotten this link from the board here: http://www.nytimes.com/2006/10/17/s...gin&adxnnlx=1161121848-0wSIcQctEu20L0udSBIM/Q Of course I haven't read the Russian studies, so this really is going on faith: In Kamchatka, wild trout (or real trout) are abundant, fierce and incredibly adaptable, their genes undiluted by hatcheries. After years of studying these fish, Russian biologists have established a surprising fact. A river’s stock of resident rainbow trout and its stock of sea-run steelheads are not just different forms of the same species. They are members of the same population. In 2004, Maltsev and other scientists observed them spawning together, small-river trout on redds with heavy, sea-run fish. DNA analysis confirms rainbow trout can form one complex population, from mountain headwaters to the high seas.