A faunistic and ecological survey of the littoral Cladocera of Canada

Abstract

A total of 356 samples was collected and analysed from all the provinces and Northwest Territories of Canada. Nearly 2000 microscopic slides, mostly identified to the level of species, representing the littoral Cladocera of Canada were prepared. The samples, slides, and sorted populations are deposited in the Invertebrate collection of the National Museum of Natural Sciences, Ottawa, and form an objective standard for the identification of these animals for the interested biologist. During this study, 80 taxa of littoral cladocerans were recorded which includes all the species reported from Canada so far. Of these, three species are new to science. The distribution of species in Canada is given, providing several new occurrence records in the provinces and showing regional trends in the distribution. Outstanding taxonomic and morphological features, and the variation exhibited by some species are discussed. The differences between North American populations and European populations of some species are noted. The relationship between pH, total dissolved solids (TDS), and the diversity of littoral cladocerans as well as the substrate preferences exhibited by them, during this survey, are also discussed. Past Canadian records of chydorid cladocerans are critically examined and a list of species that have subsequently been synonymized or are of dubious validity is given.