Skip booklet index and go to page content

Round Pigtoe (Pleurobema Sintoxia)

Special Significance of the Species

There are 31 species in the genus Pleurobema (recognized by Williams et al. 1993), but only P. sintoxia has a range that extends into Canada. Fifteen species of Pleurobema are either listed or are candidates for listing under the U.S. Endangered Species Act (USFWS 2002). Some of these species are already presumed to be extinct. Pleurobema sintoxia is the only member of the genus that is listed as “currently stable” by the American Fisheries Society (Williams et al. 1993), although this information is now ten years old. The entire genus is disappearing rapidly, mostly due to habitat alteration from the construction of impoundments. The genera Pleurobema and Epioblasma are the most critically imperiled taxa of unionids – the protection of even the most common members of these taxa is necessary to ensure that the genera remain extant. The presence of rare mussel species is indicative of healthy waters, as the rarest species are often the most sensitive to habitat alteration. The continuing decline or disappearance of rare species is a warning of the continuing degradation of our freshwater resources.