The North American Paddlefish, or Polyodon spathula, can be found in the large rivers in the Mississippi drainage.  Specifically in Wisconsin, these species are found in the lower Mississippi and St. Croix rivers, however, they are most common in Lake St. Croix and Lake Pepin.  As of 2007, the North American Paddlefish are extirpated in four states—New York, Pennsylvania, Maryland, and North Carolina—endangered/threatened/species of concern in ten states—Texas, Oklahoma, Alabama, Virginia, West Virginia, Ohio, Wisconsin, Minnesota, North Dakota, and Montana—declining in Illinois and Nebraska, and stable in ten states—South Dakota, Iowa, Missouri, Kansas, Arkansas, Louisiana, Mississippi, Tennessee, Kentucky, and Indiana.  For a pictographic view of the distribution, see Figures 5-7 below .  As for Canada, these species have been extirpated, meaning that they no longer live in Canada but are found elsewhere.  This decline in Polyodon spathula is caused by overfishing, pollution, and modifications to the rivers such as the addition of dams.
            Polyodon spathula mainly live in freshwater, but they can also survive in water with a mixture of seawater and freshwater.  Paddlefish like to live in deep water greater than six meters and low current velocity less than five centimeters per second.  In regards to how this organism fits into its niche, little is known of the American paddlefish’s role in its ecosystem.  Only a few relationships are known about the American paddlefish.  Polyodon spathula are predators of zooplankton while being prey to other fishes, birds, and humans.  This species of fish can also be hosts to lamprey.       

Figure 5.  Paddlefish distribution in the United States and Canada.

Figure 6.  Paddlefish distribution in the United States.

Figure 7.  Distribution and summary information of the Paddlefish in Wisconsin. 

Key to Summary Information Table: 
S2=Imperiled in Wisconsin because of rarity (6-20 occurrences or few remaining individuals or acres) or because of some factor(s) making it very vulnerable to extirpation from the state
=Apparently globally secure, though it may be quite rare in parts of its range, especially at the periphery

            Numerous species also live in the same habitat as the American Paddlefish.  Among these species are Daphnia spp., Lake Sturgeon, zebra mussels, small mouth bass, catfish, bluegill, and black crappie.  Because there are so many species living in its habitat, the American Paddlefish has had to accommodate in order to be able to locate its food source, the Daphnia spp.  To find out more about how the Paddlefish does this, proceed to the Adaptation page.



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