Occurrence and distribution of littoral Chydoridae (Crustacea, Cladocera) in Ontario, Canada, and taxonomic notes on some species

Of the 39 species of littoral Chydoridae reported from Ontario, 7 are new for the province, and 2 are new to Canada. Higher species numbers per locality were found in the soft-water lakes of the Precambrian Shield areas as compared with the harder-water lakes of southwestern Ontario. Several species exhibited distinct differences from the original descriptions based on European material, and critical taxonomic features of these species are described and discussed.