Maureen G. Walsh Randall J. Smith Jr. Amy B. Welsh Jennifer M. Questel 2012 The most recent Ponto-Caspian species to invade the Laurentian Great Lakes is the crustacean <i>Hemimysis anomala</i>, first reported in 2006. A previous study described three haplotype groups (A, B, C) of <i>H. anomala</i> in native and invaded areas within Europe, but only one haplotype (A1) in a sample from Lake Michigan. Our study expands these results to additional populations in the Great Lakes basin, and evaluates relationships among North American and European populations. A 549-bp fragment of themitochondrial cytochrome oxidase I (COI) gene was analyzed from populations of <i>H. anomala</i> in Lakes Ontario, Erie, Huron, and the St. Lawrence River.Two different haplotypes, A1 and B1,were observed in the sampled populations of <i>H. anomala</i> and in a previous analysis from <i>H. anomala</i> in Oneida Lake (New York). Our results, in contrast with a previous study, detect an additional haplotype in North America. application/pdf 10.1016/j.jglr.2011.11.004 en Elsevier New data on mitochondrial diversity and origin of <i>Hemimysis anomala</i> in the Laurentian Great Lakes article