The undisputed king of the depths in Lake Superior is the Lake Sturgeon (Acipenser fulvescens). These prehistoric-looking giants can grow to incredible sizes, with some individuals reaching over 6 feet in length and weighing more than 100 pounds. They are long-lived creatures, with some documented to be over 100 years old. While the Lake Sturgeon is the largest by mass and length, the Lake Trout is the largest "game fish" most frequently targeted by anglers, sometimes reaching weights of 40 to 60 pounds. In 2026, conservation efforts for the Lake Sturgeon are critical, as they are a threatened species in many parts of the Great Lakes. Their presence is a sign of a healthy aquatic ecosystem, as they require clean, oxygen-rich water and specific gravel beds for spawning. Seeing one of these "living fossils" in the wild is a rare and majestic experience, serving as a reminder of the ancient biological history contained within the cold, vast waters of the world's largest freshwater lake by surface area.