Distribution of the Mudpuppy, Necturus maculosus, in Minnesota in relation to postglacial events

Abstract

The Mudpuppy, Necturus maculosus, dispersed through Minnesota from a Mississippi River refuge following deglaciation and now inhabits drainages physically isolated from that river system. Access to the Hudson Bay drainage was provided by drainage from glacial Lake Agassiz through the River Warren, following the course of the present Red and Minnesota rivers. Access to Lake Superior was available through several routes, but most directly by drainage of meltwaters through the valleys of the present Brule and St. Croix rivers. There are no confirmed records of the Mudpuppy in the Mississippi River above St. Anthony Falls. Routes for colonizing that region were temporarily available both early and later during the postglacial period. Finally, whether or not the Mudpuppy occurs above barrier falls in tributaries to Lake Superior's North Shore has a bearing on interpretations of its postglacial dispersal.