Pisidium casertanum has a cosmopolitan distribution, and is the most widely distributed mollusc in the world (Mackie, 2007). It is the most abundant Canadian sphaeriid (Clarke, 1981), and is found in all parts of Canada except the northernmost Arctic islands (Mackie, 2007). It is widely distributed in British Columbia.
This species has adapted itself to a wide variety of habitats, including ponds and swamps that dry up for several months of the year, creeks with considerable current, rivers, and lakes (Herrington, 1962). In his study of the molluscs of the Canadian Interior Basin, Clarke (1973) found this species associated with a variety of bottom deposits, but predominantly mud.
Note Author: Ian Gardiner
