동해에서 요각류 섭식에 대한 독립영양 및 종속영양 원생동물의 섭식률

Abstract

Ingestion rates and prey selectivity of two calanoid copepods (Calanus sinicus and Neocalanus plumchrus) on auto-and heterotrophic protozoa were estimated in Ulleung Basin of East/Japan Sea. Both copepods ingested more heterotrophic protozoa than autotrophic protozoa, except when phytoplankton concentration was relatively high. In particular, ciliates have the potential to comprise a major dietary portion for copepod in the study area. The consumption of ciliates comprised average 38.4 % of total copepod daily carbon ration on auto-and heterotrophic protozoa. Auto-and heterotrophic protozoa in the 20-50 µm size was also the most consumed by copepods in all experiment. Copepods positively selected ciliates and HDF groups for protozoan population, and heterotrophic protozoa of over 10 µm size for size class during all experiments. Therefore, our results implicate that copepods feeding was influenced by the composition and size of potential food particles, and their behavior might be potentially control ciliates and HDF population of over 10 µm size in this study area. Conclusively, the selective feeding as well as higher grazing pressure of the copepods on heterotrophic protozoa compared to autotrophic protozoa indicates a strong coupling between copepods and the microbial food web in this study area.