Acipenser is a genus of fish commonly known as sturgeons. These ancient fish are characterized by their elongated bodies, bony scutes instead of scales, and long snouts. They are primarily found in freshwater and brackish environments across the Northern Hemisphere, particularly in rivers and coastal areas. Sturgeons are known for their unique reproductive habits, as they migrate upstream to spawn. Many species within the Acipenser genus are critically endangered due to overfishing, habitat loss, and pollution. They are also famous for producing caviar, a delicacy made from their roe.