Little information exists on the life history of Pleurobema rubrum (Pyramid Pigtoe). We determined fish hosts and made observations on the conglutinate release of Pyramid Pigtoe. From 2003 to 2005, fourteen Pyramid Pigtoe individuals were collected during mussel sampling on the Green River, KY and held in captivity. In June of 2006, one captive female was observed releasing conglutinates (water temperature was 22.5 °C). Nine fish species were exposed to Pyramid Pigtoe glochidia. After 12–15 days, transformation of glochidia to juveniles occurred on 4 species from the family Cyprinidae: Cyprinella spiloptera (Spotfin Shiner), Erimystax dissimilis (Streamline Chub), Lythrurus fasciolaris (Scarlet Shiner), and Notropis photogenis (Silver Shiner). All 4 are potentially natural hosts and Spotfin Shiner appears to be the most suitable host fish for propagation purposes.