Geographic Variation in Naupliar Growth and Survival in a Harpacticoid Copepod.

Newly hatched nauplii of Scottolana canadensis (Willey) collected from two locales in Maine were larger than Maryland nauplii when females were reared under identical conditions (20[deg]C and high food concentration, 2.5 [times] 105 algal cells ml[minus]1). Under high food concentration, Maryland nauplii had faster growth rates (log10 [mu]m h[minus]1) than Maine nauplii, but survivorship was similar. Growth rates were lower under low food concentration (0.5 [times] 105 cells ml[minus]1), and were the same for all locales, whereas survivorship of the Maine nauplii through NV was higher than the Maryland nauplii. We hypothesize that size-related differences in naupliar feeding efficiency may explain the variation in survival under low food stress.