Lake sturgeon
Acipenser fulvescens (Rafinesque, 1817)

member of the Sturgeon Family (Acipenseridae)

Lake of the Woods, Lake of the Woods County, Minnesota

Mississippi River (Pool 4), Minnesota 1996

Young of the Year

 

 


Name


Habitat


Size/Age

Food

Predators

Reproduction

Conservation

 

 

 

 

What's In a Name?
Lake sturgeon: refers to the habitat in which it is often found; "sturgeon" came from an old German word for these types of fish

Acipenser (Ay-see-pen´-sir) means "sturgeon" in Latin
fulvescens (full-vess´-sins) means "reddish yellow" in Latin

       

    Where Do They Live?
In the 1800s, lake sturgeons were abundant in many lakes and large rivers in the state. Today they are a very rare find. They are present in limited numbers in the lower Mississippi, St. Croix, Minnesota, Red, and Rainy rivers. They also inhabit Lake Superior, Lake of the Woods, and some lakes in the Boundary Water Canoe area. In rivers, lake sturgeons tend to live in the deepest parts of the channels or in deep pools.
       

   

How Big Do They Get?
How Long Do They Live?
The lake sturgeon is the largest fish found in Minnesota. They grow fairly slowly but live a long time and reach very large sizes. Many lake sturgeon reach over 50 kg (over 100 lbs). The big ones weigh in at over 100 kg (220 lbs) and can be over 2 m (6.5 ft) long. Lake sturgeons live a very long time. We know of several that were over 80 years old when captured. We suspect that in the old days many lived to be over 100 years old. The Minnesota record for this fish is 107.3 kg (236 lbs) and 2.5 m (8ft) long. It was netted in Lake-of-the-Woods in 1911. The official angling record is 42.7 kg (94 lbs, 4 oz) and was caught in the Kettle River.

       
    What Do They Eat?
Young lake sturgeons eat a variety of small crustaceans like waterfleas and small aquatic insect larvae until they reach about 180 mm (7 in) in length. At this stage, they start to include many of the same items that the adults eat. Adults suck their food up from the lake or river bottom. Their diet commonly includes small clams, snails, crayfish, sideswimmers, aquatic insect larvae, algae, and other plant matter.
       
   

What Eats Them?
There are many different fish that prey upon the eggs of the lake sturgeon, such as catfish, suckers, and, on occasion, other sturgeons. Both the young and adult sturgeons because of their size have very few predators. There are two main ones: parasitic lampreys and humans.

       
   

How Do They Reproduce?
The spawning season for lake sturgeon in Minnesota spans the months of April, May, and sometimes June. Males do not reach sexual maturity until they are 20 years old, and females are usually 25 years old before they spawn for the first time. Females only spawn every 4 to 6 years, while the males usually spawn every other year. Lake sturgeon generally migrate long distances to reach suitable spawning habitat. Dams and other navigation devices can interfere with this migration and force sturgeon to spawn in unsuitable areas. Males arrive at the gravel spawning sites before females. When spawning begins, several male will swim along side a female, usually going against the current. The female deposits her eggs and the males fertilize them at the same time. Each spawning act is brief, but the entire process can last up to 8 hours and can be spread out over a couple of days. A single female can lay from 50,000 to 1,000,000 eggs, depending on her size. Eggs hatch in 5-10 days depending on water temperature.

       
   

Conservation and Management
Lake sturgeons currently are listed as a species of special concern. Overfishing, habitat alteration, and pollution turned this species from one of our most abundant large fishes into one of our rarest. Lake sturgeon have been reintroduced to the Red River system, and recovery of populations in the upper St. Croix and Rainy river systems has been reasonably good. Poor water quality and migration barriers (locks and dams) continue to prevent recovery in the lower Mississippi River. At the end of the 1800s, caviar (eggs) of this species were in high demand.

 

 


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Permission is granted for the non-commercial educational or scientific use of the text and images on this Web document. Please credit the author or authors listed below.

Photographs by Konrad P. Schmidt
Text by Nicole Paulson & Jay T. Hatch in cooperation with
the Minnesota Department of Natural Resources' MinnAqua Aquatic Program

This page developed with funds from the
MinnAqua Program (Minnesota Department of Natural Resources, Division of Fisheries)
and the
Sport Fish Restoration Program (Fish and Wildlife Service, US Department of the Interior)

Maintained by Jay T. Hatch
General College and James Ford Bell Museum of Natural History
University of Minnesota, Minneapolis/St. Paul


Last updated 23 October 2002