The unique native fish that live below the surface of the Colorado River are an amazing part of the Grand Canyon itself, from the world's largest minnow - the Colorado Pikeminnow, which can grow over 6 feet long - to bonytail chub which were brought back from the brink of extinction after dwindling to only eleven known individuals. The geologic time frames that shaped the Grand Canyon also shaped the fish, with humpback chub and razorback suckers developing unusual humps and keels whose function still remain a mystery.
Large hydroelectric dams stopped the migration of fish from Baja California to the mountains of Colorado and the once highly variable, warm and muddy ricer now runs steady, clear and cold. Some Native fish still persist - at least for now.
Will the few native fishes that remain continue to survive, or will invasive aquatic species prove their undoing? Only by understanding their past, can we fully appreciate the role we play in ensuring that these species have a future.