Common name: bloodfluke planorb
Synonyms and Other Names: Planorbis glabratus Say 1818
available through www.itis.gov
Identification: Snails in the family Planorbidae have a discoidal shape with a concave, flattened spire, and oblique aperture; adults have 5 to 6 whorls (Burch and Tottenham, 1980).
Size: Adult shells generally range from 15-30 mm in diameter, but can reach 40 mm (Barbosa et al., 1968).
Native Range: Neotropical species: West Indies (including Puerto Rico), Venezuela, Suriname, French Guiana, and Brazil (Barbosa et al., 1968).
Hydrologic Unit Codes (HUCs) Explained
Puerto Rico &
Interactive maps: Point Distribution Maps
Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Biomphalaria glabrata are found here.
Table last updated 9/30/2019
† Populations may not be currently present.
Ecology: Inhabits most any type of freshwater system of lakes, rivers and creeks, in addition to marshes, temporary ponds, and irrigation and drainage ditches (Barbosa et al., 1968).
Means of Introduction: It is not known how B. glabrata was introduced in the United States.
Status: Single collections have been reported from Florida (Burch and Tottenham 1980) and Idaho (Bowler and Frest 1991), but it is not known to be established in these states. However, in North Carolina, collections of live specimens have been made at a single location over a three year period. Museum specimens have yet to be located for collections mentioned in the Burch and Tottenham (1980) and Bowler and Frest (1991) publications.
Impact of Introduction: This snail is an obligatory host for the larval stage of the blood fluke trematode parasite Schistosoma mansoni which causes the disease Schistosomiasis in humans (Morgan et al., 2001). The parasite is found throughout Africa, Venezuela, parts of Brazil, and to a lesser degree in the Caribbean region (Centers for Disease Control and Prevention, 2014). The parasite's endemic range is thought to be the Great Lakes region of central Africa (Schmidt and Rogers, 1981). The disease has not been found in the United States.
References: (click for full references)
Barbosa, F.S., E.G. Berry, H.W. Harry, B. Hubendick, E.A. Malek, W.L. Paraense, E.C. Chamberlayne, and L.J. Olivier. 1968. A guide for identification of the snail intermmediate hosts of schistosomiasis in the Americas. Pan American Health Organization, Pan American Sanit. Bur., Washington, D.C., Sci. Publ. No. 168, pp. i-ix, 1-122.
Bowler, P.A., and T.J. Frest. 1991. The non-native snail fauna of the middle Snake River, southern Idaho. Proceedings of the Desert Fishes Council 23:28-44.
Burch, J.B., and J.L. Tottenham. 1980. North American freshwater snails: species list, ranges and illustrations. Walkerana - Transactions of the POETS Society 1(3):81-215.
Centers for Disease Control and Prevention. 2014. Parasites - Schistosomiasis, Epidemiology and Risk Factors. Online at http://www.cdc.gov/parasites/schistosomiasis/epi.html. Accessed 1/29/2014
Morgan, J.A., R.J. Dejong, S.D. Snyder, G.M. Mkoji, and E.S. Loker. 2001. Schistosoma mansoni and Biomphalaria: past history and future trends. Parasitology 123 Suppl.:S211-28.
Pimentel, D. 1957. Life history of Australorbis glabratus, the intermediate snail host of Schistosoma mansoni in Puerto Rico. Ecology 38(4):576-580.
Schmidt, G.D. and L.S. Roberts. 1981. Foundations of Parasitology. 2nd edition. The C.V. Mosby Company, St. Louis, MO.
Revision Date: 8/9/2019
Peer Review Date: 8/9/2019
Benson, A.J., 2020, Biomphalaria glabrata (Say, 1818): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=1029, Revision Date: 8/9/2019, Peer Review Date: 8/9/2019, Access Date: 10/29/2020
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.