Systematics of the Daphnia pulex group: variation in an agamic complex and description of a species new to North America

A survey of genotypic diversity at 10 polymorphic enzyme loci in 855 isolates of Daphnia from three sites in northwestern Canada revealed a total of 46 genetically different clones. Three of these clones were identified as D. curvirostris and represent the first record of this taxon for North America. The remaining clones showed a continuous gradient of phenotypes from typical D. pulex to D. schodleri. These clones were shown to reproduce by obligate parthenogenesis, suggesting that the two ‘species’ are members of a single agamic complex.