Interactions between two species of marine diatoms: Effects on their individual copper tolerance

摘要: The purpose of this study was to examine the effect interaction two species marine diatoms,Skeletonema costatum (Cleve) Greville andNitzschia thermalis (Ehrenberg) Auerswald, on their individual copper tolerances. species, obtained from stock cultures in 1989, were grown together at three concentrations (1, 4 and 5 × 10−7 M added total copper). In unialgal that used as controls, grew predicted tolerance tests. However, mixed cultures,N. only exhibited growth, regardless concentration medium. Growth retardation ofS. presence ofN. attributed an inhibitory exudate. exudate appeared have been temporary, demonstrated by extended lag phase subsequent satisfactory exponential growth rate costatum. It is suggested degraded within a period d (=lag phase) because resumed. thus appears between diatom more important determining survival than its tolerance. This not case forN. thermalis. Such interactions would be unaccounted for single-species toxicity On other hand, if they are known, prediction how community includes these respond additions becomes possible.