History of the domestic sheep exact line of descent between domestic sheep and their wild ancestors is unclear. The most common hypothesis states that "Ovis aries" is descended from the Asiatic ("O. orientalis") species of mouflon. A few breeds of sheep, such as the Castlemilk Moorit from Scotland, were formed through crossbreeding with wild European mouflon. The urial ("O. vignei") was once thought to have been a forebear of domestic sheep, as they occasionally interbreed with mouflon in the Iranian part of their range. However, the urial, argali ("O. ammon"), and snow sheep ("O. nivicola") have a different number of chromosomes than other Ovis species,
Class A Wild Trout Waters Waters vary by species. For brook trout, a biomass of , including at least of brook trout less than long. Additionally, brook trout may not make up less than 75 percent of the total wild trout biomass. The requirements are the same for brown trout except that the minimum brown trout biomass is . For a stream to be Class A Wild Trout Waters for both brook trout and brown trout, the combined biomass of both species must be at least and the biomass of each species must include at least of trout less than long. Neither species may make