Sphaerium rhomboideum is endemic to North America. It is found between the parallels of 42° and 55° north latitude, extending between the Pacific and Atlantic coastal zones (Mackie, 2007). It occurs in southernmost British Columbia.
This species seems to attain its largest size and population densities in small lakes and ponds with muddy bottoms and dense vegetation (Mackie, 2007). It is found in the eddies of creeks and rivers (Herrington, 1962), while Clarke (1973) reported it from the muddy parts of large lakes and (rarely) gravel bottoms of rivers, with or without sand.
Note Author: Ian Gardiner
