This species is native to the USA, from Chesapeake Bay southward through the Gulf of Mexico (NatureServe 2009).

It has spread from its native range to other parts of the USA via ship ballast water - invading the Hudson River, New York in the 1930s, the Upper Mississippi River in the 1980s, and southern New England in the 1990s (Therriault et al. 2004). This species is thought to have spread to Europe as early as 1835, and is now found along the North Sea coasts from Germany to France, including the Thames Estuary in England. It was recently identified for the first time from the Dniester Liman, Black Sea basin (Therriault et al. 2004).