A pair of lake sturgeon in shallow waters
Ancient Fish Dwells in Rivers and Lakes
The lake sturgeon is an ancient fish, characterized by five rows of boney plates, a heavy torpedo-shaped body, four smooth barbels on the lower snout and a cartilaginous body structure. Large lake sturgeon can grow to more than 8 feet in length and weigh as much as 800 pounds. Despite the name, lake sturgeon are found on the bottoms of both lakes and rivers in Canada and the eastern half of the United States. And some have even been observed in brackish waters. The Great Lakes and St. Lawrence River basin are home to the largest populations.
Extremely long-lived, lake sturgeon can reach ages of 100 years or more. They grow rapidly in their first 10 years, but reach sexual maturity more slowly than any other freshwater fish. Males reach sexual maturity around 15-20 years; females around 20-25 years.
In the spring or early summer, depending on local water temperature, lake sturgeon migrate upstream in rivers to spawn. Females release 50,000-700,000 eggs that are fertilized by nearby males and then attach to rocky surfaces. If the eggs survive being eaten by other fish, they will hatch within 5-8 days.
Lake sturgeon generally eat leeches, snails, small clams, insects and sometimes small fish and plants. They swim slowly across the river or lake bottom, dragging their sensitive barbels. When they sense food, their tubular, toothless mouth extends to suck up food, expelling any sediment through their gills.
Although lake sturgeon were once over-exploited and some local populations are threatened or endangered, global populations remain healthy. The IUCN lists the species as one of Least Concern.