Common name: giant floater
available through www.itis.gov
Size: can reach 110 mm
Native Range: The entire Mississippi River drainage including the Missouri; St. Lawrence River drainage and Lake Champlain.
Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Pyganodon grandis are found here.
Table last updated 9/26/2021
† Populations may not be currently present.
Means of Introduction: May have been intentionally introduced.
Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.
References: (click for full references)
Mills, E.L., D.L. Strayer, M.D. Scheuerell, and J.T. Carlton. 1996. Exotic species in the Hudson River basin: A history of invasions and introductions. Estuaries 19(4):814-823.
Revision Date: 9/1/2017
Benson, A.J., 2021, Pyganodon grandis: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=2240, Revision Date: 9/1/2017, Access Date: 9/26/2021
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.