Invasion

Invasion Description

1st Tidal Record: Charles County/MD/lower Potomac River tributaries (2006, USGS Nonindigenous Aquatic Species Program 2017)

!st Nontidal Record: Dauphin County ('to the Fall Line, MD boundary)/PA/Susquehanna River (1976, USNM 147679, U.S. National Museum of Natural History 2017);

Geographic Extent

Tidal Records: Prince Georges-Charles County/MD/lower Potomac River tributaries, Piscatway Creek, Mattawoman Creek, Mallows Bay (2006-2010, USGS Nonindigenous Aquatic Species Program 2017); Charles County/MD/Nanjemoy Creek (2010, USGS Nonindigenous Aquatic Species Program 2017); Dorchester County/MD/Little Blackwater River (2006, USGS Nonindigenous Aquatic Species Program 2017).

Widespread in nontidal upper Bay tributaries, Bush, Gunpowder, Patuxent, Eastern Shore tributaries; Chester, Choptank, Nanticoke, Pocomoke Rivers, (2006, USGS Nonindigenous Aquatic Species Program 2017)