Growth interactions between marine dinoflagellates in multispecies culture experiments

摘要: The growth interactions between the marine dinoflagellates Scrippsiella faeroense (Paulsen) Balech et Soares, Prorocentrum micans Ehrenberg and Gymnodinium splendens Lebour were investigated in batch continuous-culture combinations. Generation times 1.3±0.2 days for S. faeroense; 1.6±0.1 P. 1.8 ± 0.2 G. splendens. In mixed cultures, depended strongly on ratio cell numbers of two species inoculated at start experiments. various inocula, more abundant prevailed suppressed competitor even during exponential growth. Total production forms was lowered drastically; initial generation time, however, remained or less unaffected. equal dominated over splendens, spendens micans. continuous grew independently each other stage; number regulated only by times. Competitive inhibition did not occur until maximum densities dominating had been reached. Filtration experiments indicated inhibiting effects mainly filtered culture liquids stagnating cultures: reinoculated cells all three test populations showed a somewhat reduced total production. Short lag phases spendens; following this period, population unaffected, however. show that multispecies cultures is stage nutrient competition, while an additional effect metabolic products involved. Whether caused toxic algal excretions bacterial decomposition dead could be determined. Sexual stages occurred aged both monocultures combinations influenced equilibrium competing species. results are discussed light findings authors.