Mergus Merganser Americanus is a species of duck that is commonly known as the common merganser or the American merganser. This duck can be found throughout North America, primarily near freshwater sources such as rivers and lakes. Synonyms for Mergus Merganser Americanus include the goosander, sawbill, and fish duck. The goosander nickname refers to this duck's habit of eating fish as a primary food source, while the sawbill name comes from the serrated edges of its beak which help it catch fish. Regardless of its various names, the Mergus Merganser Americanus is a striking bird with a distinctive red bill and a bold black and white plumage that sets it apart from other waterfowl species.