Lake sturgeon
The lake sturgeon is one of North America's largest freshwater fish, notable for its impressive size and longevity, with some individuals exceeding seven feet in length and weighing over 400 pounds. It has a distinctive physical appearance characterized by a long snout, a rounded body covered in bony plates called scutes, and a coloration that ranges from dark olive or gray on the back to lighter shades on the sides and underside. These fish primarily inhabit clean lake and river bottoms, where they feed on small fish and invertebrates using sensitive barbels that help detect prey.
Lake sturgeons face few natural predators due to their size and protective scutes, although they may fall victim to lampreys or smaller fish that prey on juveniles and eggs. They spawn in the spring, migrating to specific spawning grounds where females can lay millions of eggs that adhere to vegetation. Unfortunately, lake sturgeons are classified as an endangered species, largely due to overfishing, pollution, and the construction of dams that disrupt their spawning migrations. With a remarkable lifespan that can reach up to 154 years, efforts to conserve this species are crucial for maintaining its presence in North America's waterways.
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Lake sturgeon
The lake sturgeon is among the largest freshwater fish in North America, perhaps second only to the white sturgeon. The largest lake sturgeon ever caught was pulled from Lake Winnebago in 2012 and measured over seven feet (a little over than two meters) and weighed 406 pounds (184 kilograms). The lake sturgeon may also have an impressive life span. The one caught in 2012 was over 150 years old.
Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Acipenseriformes
Family: Acipenseridae
Genus: Acipenser
Species: Fulvescens
This large fish has a long snout and a long, heavy, rounded body with five rows of large scutes on its back. Scutes are bony plates. The lake sturgeon has dark olive or gray skin on its back and has lighter sides, which may be reddish. The underside is off-white to yellowish. A dorsal, or back, fin is located slightly in front of its large, pointed tail. An anal fin grows near the tail, from the bottom of the body, and a pelvic fin lies near the middle of the body on the bottom. Two large pectoral fins rest below and just behind the gills. Lake sturgeon may grow to be over seven feet (around two meters) long, and they can weigh up to 300 pounds (136 kilograms).
The lake sturgeon swims over clean lake and river bottoms of gravel, rocks, or firm sand. It feeds on small fish and invertebrates, or those creatures without backbones. From the bottom of the pointed snout of the fish hang four sensitive feelers called barbels. These help the fish detect prey in the water near the bottom. The mouth extends forward like a tube to suck in any food which the barbels detect.
Lake sturgeons face few natural enemies because of their scutes and their size. Some lampreys may attach themselves to adults and feed on their blood and tissue, which may result in the death of the sturgeons. Juveniles and eggs are most at risk for predation by smaller fish and herons. Of greater threat to sturgeons are fishing, pollution, and dams which prevent them from spawning in rivers and lakes.
Lake sturgeons spawn from April to May. During this time the fish make spawning runs, or migrate, from their homes to spawning grounds. Spawning grounds are usually in water which is about 20 feet (six meters) deep. Once they begin their run and are spawning, the sturgeons stop eating. Each female may produce millions of eggs which then stick to vegetation and stones until they hatch five to eight days later. The adults return to their homes after spawning.
The life span of a lake sturgeon may be quite long and is usally between 80 and 150 years. The record for the oldest lake sturgeon is believed to be around 154 years. Overfishing and habitat loss have caused the lake sturgeon to be an endangered species.
Bibliography
Haugen, Ashley. “Lake Sturgeon Fish Facts - Acipenser Fulvescens.” A-Z Animals, 28 May 2023, a-z-animals.com/animals/lake-sturgeon. Accessed 19 Apr. 2024.
“Lake Sturgeon (Acipenser Fulvescens).” US Fish and Wildlife Service, 4 May 2023, www.fws.gov/species/lake-sturgeon-acipenser-fulvescens. Accessed 19 Apr. 2024.