Exercise builds flavor into the flesh. Since a river fish must swim against the current just to remain stationary, it obviously needs to expend more energy than a typical lake fish. Not all river fishes oscillate their tails with equal vigor and intensity. An angler should expect less flavor in a fish that lazily wends its way along the silky bottom of a river than, say in a trout that maneuvers its course through a cascading, cold mountain brook.
** Asian Recipes