• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.14 no.3
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• pp.189-194
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• 2009

To investigate the difference in the ecological niches between Pfiesteria piscicida and Pfiesteria-like species (Cryptoperidininopsis brodyi and Stoeckeria algicida), we have observed the feeding behavior of three potential predators on abalone larvae and measured the survival rates of abalone larvae as a function of initial predator concentration. When the predators were mixed with abalone larvae, P. piscicida and C. brodyi became active and exhibited attacking behavior on abalone larvae within a few seconds. They could ingest whole soft body of abalone larvae using a peduncle. In contrast, feeding and attacking behavior were not observed from S. algicida. Survival rates in abalone larvae decreased with an increase of the initial concentration of P. piscicida and C. brodyi. These results indicate that Pfiesteria and Pfiesteria-like species displaying the very same shape and size have different ecological niche in the marine food webs, which implies that identification to species level is definitely important to understand and discriminate the ecological roles of them.