About Planorbella trivolvis (Say, 1817)
All species in the family Planorbidae have sinistral shells. For Planorbella trivolvis, the maximum width of the shell is 18 mm. This pond snail is native to North America, ranging from the Arctic regions of Canada in the north all the way south to Florida. It has also been introduced to other parts of the world. A recent genetic analysis of western United States populations of Planorbella trivolvis found that most genetic variation occurs within and among local populations, rather than between watersheds. The analysis also found that geographic distance did not predict genetic distance, a pattern that is attributed to long-distance dispersal by migratory waterfowl. This species prefers habitats that contain floating water weeds.
