North America has a rich fauna of freshwater isopods, primarily in the family Asellidae, but also smaller interstitial groups such as the family Microcerberidae. Similar to most isopods, Asellidae live under rocks, fallen leaves and vegetation in streams and lakes, or in caves or groundwater. Consequently, they are not well known to most people. The animal shown here is a species of the genus Caecidotea from Saugatuck Michigan. It lives in a small creek that flows through town.
These freshwater isopods will be the subject of a research project at the lab in the coming years, including a revision of the genus Caecidotea. A collaboration with Dr Leonardo García Vázquez from Mexico will add a broader dimension to the study because his PhD research was exploring the systematics of Caecidotea in Mexico. He recently has described a flock of new species from the central highlands of Mexico.
Lirceus is another genus of Asellidae that can be found in Michigan. We have found at least two species in our preliminary surveys. The specimen shown here is a male of Lirceus cf. tenax (cf. is used because we are not yet certain of the identification) that we collected from a wetland on the southern shore of Lake Superior in 2019.