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Species Range Habitats Effects Dreissena polymorpha (zebra mussel) eastern USA, southeastern Canada; expanding hardwater lakes and rivers strong declines in bivalves; large increases in gastropods
Corbicula fluminea (Asian clam) continental USA, except for some northern states; Hawaii lakes, rivers, and creeks strong declines in bivalves in at least some ecosystems
Potamopyrgus antipodarum (New Zealand mud-snail) Snake River, Madison River, Lake Ontario; expanding lakes, rivers, creeks, estuaries possibly competitive effects on gastropods
Orconectes rusticus (rusty crayfish) native to midwest, but introduced to north and east; expanding lakes, streams strong declines in gastropods
Neogobius melanostomus (round goby) Great Lakes; expanding large lakes, rivers, estuaries probably causes declines in nearshore mollusks
Lepomis microlophus (red-ear sunfish native to southeast, but introduced to north and west lakes, ponds strong declines in gastropods
Lepomis gibbosus (pumpkinseed sunfish) native to northeast, but widely introduced elsewhere lakes, ponds strong declines in gastropods
various aquatic plants (cf. Table 2) most bodies of water in USA and southern Canada contain at least 1 alien plant species most well lit, quiet waters probably strong effects on gastropod abundance and species composition
Taxon Common name Ceratopteris thalictroides water sprite
Salvinia spp.
Marsilea quadrifolia European water-clover
Hydrilla verticillata hydrilla
Eichornia crassipes water hyacinth
Egeria densa Brazilian waterweed
Lythrum salicaria purple loosestrife
Trapa natans water chestnut
Potamogeton crispus curly pondweed
Nasturtium officinale watercress
Myriophyllum spicatum Eurasian water-milfoil
Taxon Probable origin North American range Bivalves
Sphaeriidae
Sphaerium corneum Europe Ontario and New York to Ohio; large lakes and rivers
Pisidium amnicum Europe Great Lakes to New Jersey and Ottawa, Canada; large lakes and rivers
Pisidium henslowanum Europe scattered in Canada and northern USA
Pisidium punctiferum Central America Florida, Texas
Dreissenidae
Dreissena polymorpha Europe eastern North America, expanding; lakes and medium to large streams and rivers
Dreissena bugensis Europe eastern Great Lakes and St. Lawrence River, expanding; rivers and lakes
Corbiculidae
Corbicula fluminea southeast Asia most of USA, but scattered or absent from the coldest states; lakes, rivers, and smaller streams
Corbicula sp. 2 Asia Texas to Arizona; spring-fed streams
Gastropods
Valvatidae
Valvata piscinalis Europe Lakes Erie, Ontario, and Cayuga; Hudson and St. Lawrence Rivers
Viviparidae
Cipangopaludina chinensis
malleataJapan widely scattered in quiet waters throughout USA and southern Canada
Cipangopaludina japonica Japan widely scattered in quiet waters throughout USA and southern Canada
Pilidae
Marisa cornuarietis South or Central America Florida, Texas
Pomacea bridgesi South America Florida
Bithyniidae
Bithynia tentaculata Europe northeastern North America; lakes and rivers
Hydrobiidae
Potamopyrgus antipodarum New Zealand Snake River, Madison River (Montana), Lake Ontario; probably will spread widely
Thiaridae
Melanoides tuberculatus unknown Florida, Texas, Arizona
Melanoides turriculus Philippines Florida
Tarebia granifera Asia, Oceania Florida, Texas
Lymnaeidae
Radix auricularia Europ scattered through North America
Physidae
Physella acuta Europe unknown
Stenophysa marmorata South and Central America Texas
Stenophysa maugeriae Mexico Texas
Planorbidae
Biomphalaria glabrata South America Florida
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