A fly tied for the western lakes but these colors are also hot in the waters here in the east . The Brassy Minnow (Hybognathus hankinsoni). Brassy Minnows are a small cyprinid found in small lakes and streams throughout much of southern Canada. They love places with muddy streambeds and dense aquatic vegetation. They get their name from the brassy yellow to olive colour that they turn during spawning season. In the 1950s, scientists thought that Brassy Minnows were only found in eastern Canada, mostly in and around the Great Lakes--which made it very confusing when these fish were later found in scattered populations in BC, Alberta, and Saskatchewan. The western populations of Brassy Minnow were not connected to the eastern population, so how did they get there? Turns out, these populations are relics from the last ice age. Back then, they had access to the vast drainage of Glacial Lake Agassizís, which allowed them to spread throughout much of western Canada. When this glacier retreated, these populations were stranded, and cut off from the eastern populations of Brassy Minnow. This left a rather patchy distribution of Brassy Minnow populations in western Canada.