UBC Theses and Dissertations
The effect of copper on the life history stages of the Harpacticoid Copeod TIGRIOPUS CALIFORNICUS O'Brien, Patrick
Significant differences were found to exist in the copper tolerance of the life-history stages of the marine copepod, Tiqriopus californicus, using artificial seawater as medium. The copper response of Tigriopus to copper was found to occur predominantly over the concentration range 1.0X10⁻⁶ M to 1.5X10⁻⁵ M. The N-2 was the most sensitive and the C-6 was the most tolerant life-history stage. Copper equilibrated with the food of Tiqriopus did not significantly affect adult fecundity (between 1.0x10⁻¹⁰ and 1.0X10⁻⁶ M Cu) or mortality (between 1.0x10⁻¹⁰ and 1.0X10⁻⁵ M). Copper equilibrated with SOW did not significantly alter the rate of egg survival (between 1.0X10⁻⁹ and 1.0X10⁻⁶ M) or naupliar activity (between 1.0x10⁻⁸ and 1.0X10⁻⁶ M). Exposure to widely varying but natural ecological conditions appears to have increased the tolerance of Tigriopus to unnatural stress. The copper-manganese interaction observed for some species of phytoplankton such as Thalassiosira pseudonana was not found to hold for Tiqriopus in SOW medium. No significant reduction in copper toxicity was observed upon addition of manganese (between 1.0 X 10⁻⁶ and 1.0X10⁻⁴ M) to copper 10X10⁻⁶ M) solutions. An attempt was made to quantify the proportion of copper and manganese in biologically available forms (i.e., able to react with or pass through biological membranes) using the cation resin technique of Zorkin et al., ( 1986). It is thought that this attempt failed due to the resin columns being supersaturated with metal ions.
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