Elliptio complanata

Williams et al. (2017) include E. errans in E. complanata.

Elliptio fumata had not been recognized for over a century and was previously included with Elliptio complanata in the Apalachicola Basin in Alabama, Florida, and Georgia; but recent systematic work has shown Elliptio complanata to be a complex of species (Williams et al. 2008).

This species is the most common species in the northern Atlantic slope and is widely distributed along the Atlantic Slope from Altamaha River basin in Georgia north to the St. Lawrence River basin, and west to Lake Superior and parts of the Hudson Bay basin. It is considered stable throughout most of its range.

This species is common and widely distributed along the Atlantic Slope from Altamaha River basin in Georgia north to the St. Lawrence River basin, and west to Lake Superior and parts of the Hudson Bay basin (Burch, 1975).

In Maine (Nedeau et al., 2000), Connecticut (Nedeau and Victoria, 2003), Vermont (Fichtel and Smith, 1995), Massachusetts (Smith, 2000), and Rhode Island (Raithel and Hartenstein, 2006), this species is found throughout almost every river drainage in every county. It is widespread in Maryland including the Upper Potomac, Washington Metro, Susquehanna, Gunpowder, Chester, Choptank, and Naticoke River drainages (Bogan and Proch, 1995). It is the most common species on the south Atlantic slope, occurring in the Altamaha, Savannah, Combahee, Edisto, Ashley, Cooper-Santee, Pee Dee, Waccamaw, Cape Fear, Neuse, Pamlico, Roanoke, Chowan, James, York, Rappahannock, Occoquan, and Potomac systems from Georgia to Virginia (Johnson, 1970). It is the only mussel species known from Virginia's eastern shore on the Delmarva peninsula. It is found in 2 of 61 sites surveyed in Pee Dee River drainage (Waccamaw River, Lynches River) in South Carolina (Catena Group, 2006). In South Carolina, it is widespread in rivers from the Savannah River basin north to the Pee Dee River basin (Bogan and Alderman, 2004); Santee (Alderman, 2006). North Carolina distribution includes most Atlantic Slope river drainages from the Chowan (Alderman and Alderman, 2009) south to the Broad River, where it can be very common (Bogan, 2002). It was recently collected in the Lower Ogeechee/ Canoochee drainages in Georgia (Sukkestad et al., 2006). Reports from the Apalachicola Basin of Alabama, Florida, and Georgia by Brim Box and Williams (2000) and Heard (1979) and the Choctawhatchee, Yellow, and Conecuh-Escambia River drainages in southern Alabama by Pilarczyk et al. (2006) are now considered to be E. fumata. In the Delmarva peninsula, this species was found in the Susquehanna, Chester, Choptank, Nanticoke, Christina, Appoquiniminik, Smyrna, Leipsic, Mispillion, anc Cedar Creek systems in Delaware and Maryland (Counts et al., 1991). In the Delaware River basin, it has been recorded in all drainages (Middle Delaware- Mongaup- Broadhead, Upper Delaware, East Branch Delaware) in New York to bordering Pennsylvania (Strayer and Ralley, 1991). It occurs in Patterson Creek (North Branch Potomac drainage), West Virginia (Clayton et al., 2001; Taylor, 1985). This species was recently collected in the Opequon River (Potomac watershed) in West Virginia (Vila et al., 2003). Disjunct occurrences exist in Minnesota, near the western edge of its range, where it is found only in Lake Superior, lower St. Louis River, and lower Pigeon River (Sietman, 2003; Graf and Underhill, 1997). Similarly, although reported from Wisconsin, occurrences this far west are questionable and considered erroneous by Mathiak (1979). Also historical occurrences are known for Ohio (e.g. Tuscarawas River- OSUM spms., northern Great Lakes), but these are also questionable (Watters, 1995). It occurs throughout the Michigan upper peninsula (Goodrich and Van der Schalie, 1939). It is the most widespread and abundant species in eastern Canada secure everywhere it occurs; including all but extreme western Nova Scotia (Clarke and Rick, 1964) and throughout New Brunswick (Davis, 1999; Hanson and Locke, 2001) but Newfoundland and Prince Edward Island (Metcalfe-Smith and Cudmore-Vokey, 2004). Martel et al. (2004) recorded this species in Lac Philippe, Gatineau Park, southwestern Quebec.

Recently, zebra mussels were found in areas previously occupied by this species on the Rideau River in eastern Ontario (Schueler and