Body is heavy and torpedo shaped with a short conical snout. Young sturgeon are gray or brown dorsally with dusky dorsal and lateral blotches. Adults are gray to olive colored dorsally, white ventrally and lack the saddles or dark blotches. Scales present as minute dermal denticles and 5 rows of large bony scutes or plates. There is a single large dorsal fin. The mouth is ventral, posterior to the eyes, and lacks teeth. Four moderately short but prominent barbels present on the  snout, anterior to the mouth (Becker, 1983). Adults are generally between 3-5 feet (91-142 cm) and between 10-80 pounds (4.5-36.5 kg) with the largest being 168 pounds 0 ounces (76.2 kg), measuring 69 inches (175.26 cm) long (IGFA, 2018). The Minnesota state record is 94 pounds 4 ounces (42.75 kg) and 70 inches (177.8 cm) long (MN DNR, 2018).

The sturgeon family (Acipenseridae) contains 27 different species in 4 genera. The largest genus is Acipenser which consists of 17 species of which only the lake sturgeon spends its entire lifecycle within freshwater (Peterson et al. 2007). The Lake Sturgeon is most closely related to the Shortnose Sturgeon, Acipenser brevirostrum (Hilton et al. 2011). The oldest fossils date back to the mid-Cretaceous (Vavrek et al. (2014); Grande and Hilton (2006) described a very well preserved fossil from the Upper Cretaceous.

Lake Sturgeon are limited to north- central and north- eastern parts of North America, reaching as far North as up near the Arctic Circle and down the Mississippi River to the state of Mississippi (Scott & Crossman, 1973).

Lake Sturgeon inhabit highly productive shallow areas of large lakes and rivers generally in waters between 15-30 feet (4.56-9.0 meters) but have been taken as deep at 140 feet (43 meters). The preferred substrate consists of gravel and mud or just mud (Scott & Crossman, 1973).

Lake Sturgeon feed on small, benthic, organisms. They  swim along the bottom using their barbels to locate food. If they suck up inedible items such as rocks and mud, they are expelled from the mouth or passed out under the opercula. Food includes crayfish, mollusks, insect larvae, nymphs, fish eggs, nematodes, leeches, amphipods, decapods and on rare occasions, fish (Peterson et al., 2007).

Lake Sturgeon are long lived fish and it is estimated that males have a lifespan of about 55 years while females live about 80 years (Peterson et al. 2007). Age determination above the age of 15 can be inaccurate and gets less precise the older the fish (Peterson et al. 2007). The oldest fish are generally found among the most northern populations which have the slowest growing individuals (Scott & Crossman, 1973).

Reproduction:

Spawning takes place in the spring during late April, extending into June depending on latitude, when water temperatures reach 55.4º F (13.0º C) to 64.4º F (18.0º C). Lake Sturgeon usually spawn in swift moving water or rapids in 2-15 feet of water. If suitable habitat is not available, spawning may take over rocky ledges or shoals that generate a lot of wave action (Scott & Crossman, 1973).

Males generally reach spawning grounds before females and will try to spawn as a fertile female enters the area, multiple males will attend to a single female. Females typically lay between 49,000–667,000 eggs but the largest females could produce over a million eggs (Peterson et al. 2007). Males reach sexual maturity between 12 and 19 years while females mature between 14 and 26 years. Males spawn every 1 to 2 years while females only spawn every 4 to 9 years; spawning frequency varies by locality (Scott & Crossman, 1973).

Lake Sturgeon are not known for traveling long distances but will move from shallow waters to deeper as it becomes warmer during the summer months and then back during the autumn before moving back to deeper water during the winter. Spawning is one exception when they will make a much longer journey to find suitable spawning locations (Scott & Crossman, 1973).

Lake Sturgeon were fished commercially during the late 1800’s and the early 1900’s; it was known for producing a very good meat and caviar. Commercial fishing has stopped due to restrictions on harvest and trade. Today the Lake Sturgeon is being reintroduced to places where it was wiped out and is being managed to bolster its population in other parts of its natural range. There is a limited sports fishery for Lake Sturgeon in Minnesota (Peterson et al., 2007).

Adult Lake Sturgeon have few predators but may be host to lampreys. Juveniles and roe are consumed by other fish species (Becker, 1983).

Lake Sturgeon were considered “vulnerable” in 1989 but their conservation status has improved (Jelks et al. 2008). They are susceptible to overharvest and poaching because they take so long to reach sexual maturity. Damming of rivers and poor water quality has also been implicated in their decline (Becker 1983). Many projects are underway to improve Lake Sturgeon populations (Roseman et al. 2011).

Grande, L, Hilton, E.J. 2006. An exquisitely preserved skeleton representing a primitive sturgeon from the Upper Cretaceous Judith River formation of Montana (Acipenseriformes: Acipenseridae: N. Gen and Sp.). Journal of Paleontology 80: 1-39.

Hilton, E.J., Grande, L., Bemis, W.E. 2011. Skeletal Anatomy of the Shortnose Sturgeon, Acipenser brevirostrum Lesueur, 1818, and the Systematics of the Sturgeons (Acipenseriformes, Acipenseridae). Fieldiana: Life and Earth Sciences No. 3: 1-168.

Scott, W.B., Crossman, E.J. 1973. Freshwater Fishes of Canada. Fisheries Research Board of Canada. Bulletin 184

Vavrek, M.J., Murray, A.M., Bell, P.R., 2014. An early Late Cretaceous (Cenomanian) sturgeon (Acipenseriformes) from the Dunvegan Formation, northwestern Alberta, Canada. Can. J. Earth. Sci. 51: 677-681.

Becker, George C. 1983. Fishes of Wisconsin. University of Wisconsin Press. Madison, WI.

Jelks, H. L., Walsh, S. J., Burkhead, N. M., Contreras-Balderas, S., Diaz-Pardo, E., Hendrickson, D. A., Lyons, J., Mandrak, N. E., McCormick, F., Nelson, J. S., Platania, S. P., Porter, B. A., Renaud, C. B., Schmitter-Soto, J. J., Taylor, E. B., Warren Jr., M. L. .2008. Conservation Status of Imperiled North American Freshwater and Diadromous Fishes. Fisheries, 33: 372-407

Roseman, E. F., Manny, B., Boase, J., Child, M., Kennedy, G., Craig, J., Soper, K., Drouin, R. December 2011. Lake sturgeon response to a spawning reef constructed in the Detroit river. Journal of Applied Ichthyology, 27: 66-77

Peterson, D.L., Vecsei, P., Jennings, C.A. February 2007. Ecology and biology of the lake sturgeon: a synthesis of current knowledge of a threatened North American Acipenseridae. Reviews in Fish Biology and Fisheries, 17: 59–76

International Game Fish Association - Retrieved March, 2018 - http://wrec.igfa.org/

Minnesota DNR State Records. Retrieved March 2018. https://www.dnr.state.mn.us/fishing/staterecords.html