The pattern of large dark spots looks a lot like brown trout to me, rainbow trout have finer spots. Plus the overall shape and the large/long adipose fin is typical of brown trout
its a toss up - It has no spotting on the tail visable which would indicate a rainbow trout or spots below the lateral line. The spotting on the body is large and sparse enough for a brown but not overtly so. It has the long adipose fin but there is no characteristic red tinge to the adipose. Id say Salmo trutta. You will have to catch one :).