Larval Host Use of the Fatmucket Mussel

In Minnesota, 52% of the state’s mussel species are listed as Endangered, Threatened, or of Special Concern, and 6% have been extirpated. Recent population declines have urged immediate action to be taken before native mussels and their ecosystem services are lost forever. How successful we are at conserving a species depends, in part, on our knowledge of its life history needs. As particular fish species act as suitable hosts for the parasitic larvae of mussels, conservation efforts must include sustainable host fish management. A better understanding of the relationship that native Lampsilis siliquoidea, a rare species in parts of its range, has with fishes can assist natural resource managers in maintaining this mussel and its ecosystem services. The purpose of this research was to expand our knowledge of the Fatmucket’s (L. siliquoidea) breadth of host use by performing laboratory tests on previously untested fishes. Species from unstudied fish families, including Centrarchidae, Esocidae, Percidae, Cyprinidae, Catostomidae, and Gasterosteidae, were examined. Standard methods for identifying suitable Fatmucket hosts were followed and performed at the University of Minnesota. Gravid L. siliquoidea were collected in May 2021 from Rice Creek, Ramsey County, Minnesota, and held in the laboratory. The majority of fishes were collected from the 7-county metro area between May and July. Of the 14 fish species inoculated with L. siliquoidea larvae, 7 facilitated larval development. The variety of fish species shown to be suitable hosts for the Fatmucket mussel suggests that additional hosts remain to be discovered. Conservation efforts will benefit from an improved understanding of the life history needs of L. siliquoidea, as well as the re-establishment of this species in areas where it has been extirpated.This research was supported by the Undergraduate Research Opportunities Program (UROP)