Hitching a Ride: Host Fishes of the Kidneyshell Mussel

There are 54 species of freshwater mussels in Canada and eight of these, including the Kidneyshell mussel, Ptychobranchus fasciolaris  are listed as endangered under the Canadian Species at Risk Act.  Our goal was to identify the reproductive timing windows - specifically regarding natural host encystment - for the Kidneyshell mussel in the Ausable River in southwestern Ontario, Canada.  A minimum of four seine hauls were taken just downstream of a 300 m² mussel plot weekly or monthly during the open water period in 2012-13.  Vouchers were taken of Etheostoma blennioides, E. nigrum, and Percina maculata, which are suspected hosts for the Kidneyshell mussel. Fish vouchers where examined for the presence of glochidia on the body, fins and gills and if found, these glochidia were photographed and measured (length, height, hinge length).  To date, 247 fishes have been vouchered, and glochidia were observed on 11%. A total of 76 glochidia were found and 12 of these were classified as Kidneyshell using a Discriminant Function Analysis.  Encystment occurred on E. nigrum and P. maculata from early September to mid November.  This type of mussel life history information is limited in Ontario and it is required to facilitate the recovery of the Kidneyshell mussel in Canada.