Henry A. Vanderploeg David M. Warner Jeffrey S. Schaeffer Stuart A. Ludsin Randall M. Claramunt Thomas F. Nalepa Steven A. Pothoven 2012 We compared <i>Bythotrephes</i> population demographics and dynamics to predator (planktivorous fish) and prey (small-bodied crustacean zooplankton) densities at a site sampled through the growing season in Lakes Michigan, Huron, and Erie. Although seasonal average densities of <i>Bythotrephes</i> were similar across lakes (222/m² Erie, 247/m² Huron, 162/m² Michigan), temporal trends in abundance differed among lakes. In central Lake Erie where <i>Bythotrephes</i>' prey assemblage was dominated by small individuals (60%), where planktivorous fish densities were high (14,317/ha), and where a shallow water column limited availability of a deepwater refuge, the <i>Bythotrephes</i> population was characterized by a small mean body size, large broods with small neonates, allocation of length increases mainly to the spine rather than to the body, and a late summer population decline. By contrast, in Lake Michigan where <i>Bythotrephes</i>' prey assemblage was dominated by large individuals (72%) and planktivorous fish densities were lower (5052/ha), the <i>Bythotrephes</i> population was characterized by a large mean body size (i.e., 37–55% higher than in Erie), small broods with large neonates, nearly all growth in body length occurring between instars 1 and 2, and population persistence into fall. Life-history characteristics in Lake Huron tended to be intermediate to those found in Lakes Michigan and Erie, reflecting lower overall prey and predator densities (1224/ha) relative to the other lakes. Because plasticity in life history can affect interactions with other species, our findings point to the need to understand life-history variation among Great Lakes populations to improve our ability to model the dynamics of these ecosystems. application/pdf 10.1016/j.jglr.2011.10.003 en Elsevier Influences on <i>Bythotrephes longimanus</i> life-history characteristics in the Great Lakes article