Physella acuta

In this database, we follow the Freshwater Mollusk Conservation Society (FMCS) which includes Physella virgata, P. mexicana, and P. winnipegensis as junior synonyms of Physella acuta; P. heterostropha, P. integra, and P. cubensis are still considered distinct species (FMCS 2021). Placement in the genus Physella is based on genetic testing and the priority of Physa fontinalis as the type species for Physa (Wethington and Lydeard 2007, FMCS 2021).

The entire family Physidae is in need of revision. Preliminary work suggests that type specimens do not match figures in original descriptions or subsequent guides. At the present time it is difficult to assess the taxonomic status of most of these species. There is some question as to whether this species is a North American native introduced to Europe or vice versa. A study of molecular phylogeny of the family Physidae conducted by Wethington and Lydeard (2007) resulted in proposed monophyly of the family and supported six major clades, each with a corresponding difference in penial morphology; with Physa acuta falling within the type c group. Further, Wethington and Lydeard (2007) concluded that P. acuta, P. heterostropha, P. integra, P. virgata, P. cubensis and P. integra niagarensis to constitute an exclusive clade, and all are attributed to one phylogenetic species, to which the valid name P. acuta applies.

Dillon et al. (2002) found no evidence of reproductive isolation between Physella acuta and the American Physella heterostropha and Physa integra indicating P. acuta is native to North America and introduced elsewhere making P. heterostropha and P. integra junior synonyms. This is supported by Anderson (2003) who also synonymizes P. heterostropha with P. acuta. Taylor (2003) lists this species as Haitia integra. Taylor (2003) also describes a species that is potentially extinct, Physella hemphilli, based upon specimens from Coeur D'Alene Lake in Idaho, but this may be a synonym or variety of Physa heterostropha which Wethington and Lydeard (2007) synonymize with Physa acuta. Physa natricina was previously named a junior synonym of P. acuta based on shell characteristics from the holotype and paratypes as well as soft tissue and shell characteristic comparisons with Physidae museum specimens (Rogers and Wethington 2007), but recognized as a valid taxon by Gates et al. (2013).

This species is likely a European native that has been widely introduced around the world and is both common and abundant. This species has a wide distribution, presumed large population, occurrence in a number of protected areas, tolerance of a broad range of habitats, tolerance to habitat modification, lack of substantial immediate threats, and because it is not in decline or is unlikely to be declining fast enough to qualify for listing in a more threatened category.

Burch (1989) cites Physa acuta as occurring in Europe, Mediterranean regions, and Africa; and widely introduced into Australia, Hawaii, and the continental United States. As Physa cubensis, now considered a synonym, it is widely distributed in the West Indies, Central America, and northern South America, and it occurs throughout Florida and adjacent Alabama and Georgia (Thompson, 1999). As Physa cubensis, considered a synonym, it is widely distributed in the West Indies, Central America, and northern South America, and occurs throughout Florida and adjacent Alabama and Georgia (Thompson, 1999). Burch (1989) lists several synonyms including P. heterostropha heterostropha from Nova Scotia to Ontario; New England to Ohio, Tennessee and the Virginias; and the Bahamas; P. heterostropha halei from Illinois, Missouri, Kansas, Arkansas and Texas; P. integra integra from Quebec to Manitoba, Canada, and the Great Lakes states, Iowa, South Dakota, Tennessee, Kentucky, and West Virginia; P. integra integra morph walkeri from Quebec, Ontario and the Great Lakes states; P. integra brevispira from New York, Ohio, Wisconsin and Minnesota; P. virgata virgata from Nebraska west to California, east to Texas and into Mexico; P. virgata virgata morph parva from Iowa west to California, east to Texas and north to Kansas; P. virgata anatina from Wisconsin and South Dakota southwest to Colorado and Nevada; Texas and Arkansas north to Illinois and Nebraska; P. virgata berendti from Wyoming to California, southeast to Texas and Mexico and north to Kansas; P. virgata concolor from Manitoba and Wisconsin to Idaho; P. virgata rhyssa from California, New Mexico and Texas into Mexico. It is considered globally invasive with introduced populations in Europe, Asia, Australia (Madsen and Frandsen, 1989), Africa (Appleton, 2003), and recently Lake Titicaca in Peru (Albrecht et al., 2009).

Burch (1989) cites P. cubensis cubensis as Bahamas, Cuba, Jamaica, Puerto Rico, the West Indies, Honduras, and Florida; with P. cubensis peninsularis in Florida. Taylor (2003) lists Haitia [= Physa] cubensis from the Bahamas; Cuba; Jamaica; Hispaniola; Puerto Rica; less abundant in Lesser Antilles as far S as Martinique; as H. integra, Great Lakes (Minnesota, Michigan) and South Dakota and North Dakota. In Indiana, Pyron et al. (2008) list it statewide. In Missouri, Wu et al. (1997) list (as P. heterostropha) across the Ozark Region and some Prairie Region near the Mississippi River (Carter, Crawford, Dent, Hickory, Howell, Knox, Laclede, Lincoln, Morgan, Newton, Oregon, Pettis, Pike, Reynolds, Ripley, St. Louis, Ste. Genevieve, Shannon, Stone, Washington, Wright Cos.); and (as P. anatina) widely (Adair, Andrew, Atchison, Audrain, Bates, Boone, Buchanan, Caldwell, Camden, Carroll, Cass, Chariton, Clay, Cooper, Crawford, Daviess, Dent, Dunklin, Franklin, Gasconade, Harrison, Holt, Howard, Howell, Iron, Jefferson, Johnson, Lincoln, Linn, Livingston, Macon, Mississippi, Montgomery, New Madrid, Nodaway, Oregon, Pemiscot, Pettis, Phelps, Pike, Platte, Polk, Pulaski, Putnam, Ralls, Ray, Reynolds, Ripley, St. Charles, St. Francois, St. Louis, Saline, Schuyler, Scott, Shannon, Stoddard, Warren, Washington, Wayne, Worth Cos.) except SW Ozarks; and P. halei statewide (Audrain, Barry, Bates, Bollinger, Boone, Butler, Callaway, Cape Girardeau, Carroll, Carter, Cass, Clay, Cole, Cooper, Crawford, Dade, Dallas, De Kalb, Dent, Dunklin, Gasconade, Greene, Henry, Hickory, Holt, Howard, Iron, Jackson, Jefferson, Knox, Laclede, Lincoln, McDonald, Macon, Madison, Miller, Mississippi, Moniteau, Montgomery, New Madrid, Nodaway, Oregon, Ozark Pemiscot, Perry, Pettis, Pike, Randolph, Ray, Reynolds, Ripley, St. Charles, St. Francois, St. Louis, Ste. Genevieve, Saline, Scott, Shannon, Stoddard, Warren, Washington, Wayne, Webster, Wright Cos.); and (as P. peninsularis) from Holt and St. Louis Cos.; nominal acuta from Butler, Carter, Grundy, Hickory, Holt, Howell, Jackson, Linn, Oregon, and St. Francois Cos. In Alabama (as P. heterostropha) it is statewide and common (Mirarchi, 2004). Blair and Sickel (1986) documented P. integra in 2 of 44 sites and P. heterostropha in 4 of 44 sites in Land Between the Lakes (between Cumberland River (Lake Berkeley) and Tennessee River (Kentucky Lake)), Tennessee. It occurs at the Savannah River Power Plant, Aiken, South Carolina (Wood, 1982). Kentucky: Kentucky, Cumberland, Licking, Green, Salt (also Rosewater, 1959), Ohio drainages (Branson and Batch, 1981; 1983; 1987). Schwartz and Meredith (1962) list P. heterostropha on the Blackwater and Laurel Fork Rivers, West Virginia. Wu and Beetle (1995) list Wyoming (as P. heterostropha) statewide: Albany, Big Horn, Campbell, Carbon, Converse, Fremont, Goshen, Johnson, Laramie, Lincoln, Sheridan, Sublette, Sweetwater, Teton, Uinta Cos. and Yellowstone National Park; as P. integra from plains Cos. Carbon, Fremont, Hot Springs, Laramie, Natrona, and Weston, and (as P. anatina) in Hot Spring Co.. Wu and Liu (2001) list it from Cloud and Nemaha Cos., N of the Kansas River and Clark and Comanche Cos. on the SW Kansas border, Kansas. Wu and Liu (2001) list Kansas records (as P. halei) from Chautauqua, Clark, Coffey, Harvey, Jefferson, adn Phillip Cos.. Branson (1966) cites Spring River drainage, Kansas and Missouri. Wu (2005) documented it in Nebraska (as P. heterostropha) in north central Cherry, Logan, and Rock Cos.; as P. halei in Custer, Dundy, and Garden Cos.; and nominally scattered near the Mississippi and large rivers in the E in Dakota, Gage, Greeley, Keith, Nemaha, Pawnee Cos. Pearce and Evans (2008) cite Plummers Island (Middle Potomac), Maryland. In Pennsylvania, it is statewide and common (Evans and Ray, 2010).