RELATIONSHIPS BETWEEN COPPER CONCENTRATIONS IN LARVAE OF PLECTROCNEMIA-CONSPERSA (CURTIS) (TRICHOPTERA) AND IN MINE DRAINAGE STREAMS

Elevated copper concentrations were determined for single larvae of Plectrocnemia conspersa in a copper-rich stream. Although larval copper concentration was reduced by at least 50% after clearing gut contents, its exponential decrease with increasing body weight remained unchanged. Analysis of instar V larvae from different sampling stations showed a steep increase in the concentration of copper in the larvae with that in the water at lower stream water concentrations, followed by a progressively less steep increase at higher stream concentrations. When captive larvae from a clean stream were introduced into a mine drainage stream, the amount of copper in fed and unfed larvae steadily increased, suggesting metal uptake from water and food. Survival and growth were comparable for introduced and captive resident larvae suggesting copper tolerance to be a general characteristic of P. conspersa. © 1990.