Overview
The Lake Sturgeon (Acipenser fulvescens) is the colossal, ancient monarch of North America’s Great Lakes. Surviving virtually unchanged since the age of the dinosaurs over 150 million years ago, this armored giant is the largest and longest-lived freshwater fish in the Great Lakes system, with matriarch females known to live for over 150 years.
Biology and Physical Characteristics
Acipenser fulvescens has an elongated, torpedo-shaped body covered in five longitudinal rows of hard, bony armor plates (scutes) instead of scales. Its head terminates in a conical, upturned snout flanked by four sensitive, whisker-like sensory barbels, followed by an extendable, toothless suction mouth that drops down like an accordion to vacuum up benthic invertebrates from lake beds.
Behavior and Ecology
A slow, deliberate bottom-cruiser, the Lake Sturgeon glides inches above sandy and gravelly substrates, dragging its barbels to detect the chemical scents and bioelectric fields of burrowing mayfly larvae, freshwater clams, and leeches. Reproduction is exceptionally slow: females do not reach sexual maturity until they are 20 to 25 years old and spawn only once every four to seven years in rushing river rapids.
Conservation and Human Impact
Classified as Endangered by the IUCN, Lake Sturgeon populations collapsed by over 95% in the late 19th and early 20th centuries due to commercial caviar exploitation, slaughter by commercial netters, and hydroelectric dam construction that blocked ancestral river spawning runs. Decades of collaborative stocking, dam removal, and riverbed restoration are now fostering slow, steady recoveries.
Interesting Factoid
Lake Sturgeons are the oldest and longest-lived fish in North America; individual females alive today were swimming in Lake Superior during the American Civil War, living well past 150 years of age.